Improving the Through-Thickness Thermal Conductivity of Carbon Fiber/Epoxy Laminates by Direct Growth of SiC/Graphene Heterostructures on Carbon Fibers

Poor thermal conductivity in the through-thickness direction is a critical limitation in the performance of carbon fiber-reinforced polymer (CFRP) composites over a broad range of applications in the aviation industry, where heat dissipation is required (e.g., battery packs, electronic housing, and heat spreaders). In this work, it is demonstrated for the first time that a hierarchical network of vertically oriented graphene nanoflakes (GNFs), with nanoconfined silicon carbide (SiC) nanocrystals, self-assembled on carbon fibers (CFs) can provide significant improvement to the thermal conductivity (TC) of CFRPs in the through-thickness direction. The vertically aligned SiC/GNF heterostructures were grown directly on CFs for the first time by single-step plasma-enhanced chemical vapor deposition (PECVD) employing tetramethylsilane (TMS) and methane (CH₄) gases at temperatures of 800 and 950 °C. At the deposition temperature of 950 °C, the controlled introduction of SiC/GNF heterostructures induced a 56% improvement in through-thickness TC over the bare CFRP counterparts while simultaneously preserving the tensile strength. The increase in thermal conductivity is accomplished by SiC nanocrystals, which serve as linkage thermal conducting paths between the vertical graphene layers, further enhancing the smooth transmission of phonons in the vertical direction. The work demonstrates for the first time the unique potential of novel SiC/GNF heterostructures for attaining strong and thermally conductive multifunctional CFRPs.

Pulsed Electrolysis with a Nickel Molecular Catalyst Improves Selectivity for Carbon Dioxide Reduction

Pulsed electrolysis can significantly improve carbon dioxide reduction on metal electrodes, but the effect of short (millisecond to seconds) voltage steps on molecular electrocatalysts is largely unstudied. In this work, we investigate the effect pulse electrolysis has on the selectivity and stability of the homogeneous electrocatalyst [Ni(cyclam)]²⁺ at a carbon electrode. By tuning the potential and pulse duration, we achieve a significant improvement in CO Faradaic efficiencies (85%) after 3 h, double that of the system under potentiostatic conditions. The improved activity is due to in situ catalyst regeneration from an intermediate that occurs as part of the catalyst's degradation pathway. This study demonstrates the wider opportunity to apply pulsed electrolysis to molecular electrocatalysts to control activity and improve selectivity.

Friction reducing ability of a poly-l-lysine and dopamine modified hyaluronan coating for polycaprolactone cartilage resurfacing implants

Frictional properties of cartilage resurfacing implants should be sufficiently low to limit damaging of the opposing cartilage during articulation. The present study determines if native lubricious molecule proteoglycan 4 (PRG4) can adsorb onto a layer-by-layer bioinspired coating composed of poly-l-lysine (PLL) and dopamine modified hyaluronic acid (HADN) and thereby can reduce the friction between implant and articular cartilage. An ELISA was developed to quantify the amount of immobilized human recombinant (rh)PRG4 after exposure to the PLL-HADN coating. The effect on lubrication was evaluated by comparing the coefficient of friction (CoF) of bare polycaprolactone (PCL) disks to that of PLL-HADN coated PCL disks while articulated against cartilage using a ring-on-disk geometry and a lubricant solution consisting of native synovial fluid components including rhPRG4. The PLL-HADN coating effectively immobilized rhPRG4. The surface roughness of PCL disks significantly increased while the water contact angle significantly decreased after application of the coating. The average CoF measured during the first minute of bare PCL against cartilage exceeded twice the CoF of the PLL-HADN coated PCL against cartilage. After 60 min, the CoF reached equilibrium values which were still significantly higher for bare PCL compared to coated PCL. The present study demonstrated that PCL can effectively be coated with PLL-HADN. Additionally, this coating reduces the friction between PCL and cartilage when a PRG4-rich lubricant is used, similar to the lubricating surface of native cartilage. This makes PLL-HADN coating a promising application to improve the clinical success of PCL-based cartilage resurfacing implants.

Meta-QTLs for multiple disease resistance involving three rusts in common wheat (Triticum aestivum L.)

In wheat, multiple disease resistance meta-QTLs (MDR-MQTLs) and underlying candidate genes for the three rusts were identified which may prove useful for development of resistant cultivars. Rust diseases in wheat are a major threat to global food security. Therefore, development of multiple disease-resistant cultivars (resistant to all three rusts) is a major goal in all wheat breeding programs worldwide. In the present study, meta-QTLs and candidate genes for multiple disease resistance (MDR) involving all three rusts were identified using 152 individual QTL mapping studies for resistance to leaf rust (LR), stem rust (SR), and yellow rust (YR). From these 152 studies, a total of 1,146 QTLs for resistance to three rusts were retrieved, which included 368 QTLs for LR, 291 QTLs for SR, and 487 QTLs for YR. Of these 1,146 QTLs, only 718 QTLs could be projected onto the consensus map saturated with 2, 34,619 markers. Meta-analysis of the projected QTLs resulted in the identification of 86 MQTLs, which included 71 MDR-MQTLs. Ten of these MDR-MQTLs were referred to as the 'Breeders' MQTLs'. Seventy-eight of the 86 MQTLs could also be anchored to the physical map of the wheat genome, and 54 MQTLs were validated by marker-trait associations identified during earlier genome-wide association studies. Twenty MQTLs (including 17 MDR-MQTLs) identified in the present study were co-localized with 44 known R genes. In silico expression analysis allowed identification of several differentially expressed candidate genes (DECGs) encoding proteins carrying different domains including the following: NBS-LRR, WRKY domains, F-box domains, sugar transporters, transferases, etc. The introgression of these MDR loci into high-yielding cultivars should prove useful for developing high yielding cultivars with resistance to all the three rusts.

Zero-Gap Bipolar Membrane Electrolyzer for Carbon Dioxide Reduction Using Acid-Tolerant Molecular Electrocatalysts

The scaling-up of electrochemical CO₂ reduction requires circumventing the CO₂ loss as carbonates under alkaline conditions. Zero-gap cell configurations with a reverse-bias bipolar membrane (BPM) represent a possible solution, but the catalyst layer in direct contact with the acidic environment of a BPM usually leads to H₂ evolution dominating. Here we show that using acid-tolerant Ni molecular electrocatalysts selective (>60%) CO₂ reduction can be achieved in a zero-gap BPM device using a pure water and CO₂ feed. At a higher current density (100 mA cm^-2), CO selectivity decreases, but was still >30%, due to reversible product inhibition. This study demonstrates the importance of developing acid-tolerant catalysts for use in large-scale CO₂ reduction devices.

Clinical Profile and Prevalence of H Pylori, Iga-Ttg, and Spectrum of Duodenal Abnormalities in Non Ulcer Dyspepsia

The Rome IV criterion for a diagnosis of NUD is chronic or recurrent epigastric pain within the last 3 months and an onset of symptoms at least 6 months prior to presentation. The term functional Dyspepsia and idiopathic dyspepsia are often used as well. Symptoms include ulcer-like dyspepsia; gastroparetic-like (nausea, early satiety, and post-prandial pain), and undifferentiated. Pathogenesis of NUD is not completely known yet. Several mechanisms have been proposed to be responsible for these symptoms. Although there is strong evidence of an association between H. pylori infection and NUD, Celiac Disease and NUD. Being a tropical country, the prevalence of infections is parasitic cause. Dyspepsia is likely to be more in India. However, the present data from India as scares in literature. Hence the present study was planned to decipher the clinical profile, prevalence of H. pylori, IgA tTG, spectrum of duodenal biopsy abnormalities in NUD patients.

MATERIAL

This Descriptive Observational study was carried out in the Gastro Enterology center in GOI research institute from August 2020 to March 2021. Initially, 200 dyspepsia patients were selected. 50 patients were excluded due to various reasons. Finally, 150 patients who met the Rome 4 criteria for NUD/Functional Dyspepsia were recruited. The inclusion criteria were patients above 18 years of age, dyspepsia for >/- 6 months, and no evidence of underlying malignancy, pan gastritis, previous gastric ulcers, and pancreatitis. The patients underwent routine blood investigations like haemogram and biochemistry, Rapid Urease Test (RUT), Upper Gastro-Intestinal Endoscopy, Duodenal Biopsy, and Serum IgA-tTG antibody.

OBSERVATION

The mean age was 46.3 yrs. +/- 14.12 yrs, of which 49.3% were females and 50.70% were males. The prevalence of Epigastric Pain Syndrome (EPS) was found in 37.3%, Post Prandial Distress Syndrome (PDS) in 30.7%, and 32% had both EPS+PDS. 38% of the NUD patients were positive on Rapid Urease Test (RUT) suggesting H. pylori infection. 88.7% of NUD patients were IgA-tTG antibody negative and 11.3% serologically positive. The Duodenal biopsy was normal in 48% of patients, 21.3% had mild inflammation/duodenitis, 8% chronic duodenitis and 22.7% had various grades of Celiac Disease (as per Marsh Grading). These 22.7% showing evidence of Celiac Disease on histopathological examination showed Marsh Grade 1 in 12.7%, Grade-2 in 2%, Grade 3A in 6.7%, and Grade 3B in 1.3%. Only 17.6% of biopsy positive had IgA-tTG antibody positivity but only 4% of total cases were positive for both biopsy and IgA-tTG antibody (p-value 0.05). Eosinophilic infiltration in duodenum common in NUD patients. It was observed that 17.33% (26/150) NUD patients had duodenal eosinophilia. Further, look for the association of duodenal eosinophilia with various diseases. 33.33% (19/57) H. pylori patients had duodenal eosinophilia with p-value < 0.001. It was also observed that 7.52% (7/93) others like normal individual, Chronic duodenitis, mild inflammation/ duodenitis had Duodenal eosinophilia.

CONCLUSION

The prevalence of H. pylori and IgA-tTG antibodies in non-ulcer dyspepsia patients was 38% and 11.3% respectively. The spectrum of Duodenum biopsy abnormalities in NUD patients included mild inflammation/ duodenitis, Chronic duodenitis, and Celiac Disease. 22.7% of NUD patients had various degrees of celiac disease morphology on D2 biopsy and only 17.6% of these biopsy positive patients were positive for IgA-tTG. Only 4% of total NUD patients were positive for both biopsy and IgA-tTG antibody labeled as Celiac Disease (CeD). There is a significant association between H. pylori and duodenal eosinophilia.

Direct monitoring of single-cell response to biomaterials by Raman spectroscopy

There is continued focus on the development of new biomaterials and associated biological testing methods needed to reduce the time taken for their entry to clinical use. The application of Raman spectroscopy to the study of individual cells that have been in contact with biomaterials offers enhanced in vitro information in a potentially non-destructive testing regime. The work presented here reports the Raman spectral analysis of discreet U-2 OS bone cells after exposure to hydroxyapatite (HA) coated titanium (Ti) substrates in both the as-deposited and thermally annealed states. These data show that cells that were in contact with the bioactive HA surface for 7 days had spectral markers similar to those cultured on the Ti substrate control for the same period. However, the spectral features for those cells that were in contact with the annealed HA surface had indicators of significant differentiation at day 21 while cells on the as-deposited surface did not show these Raman changes until day 28. The cells adhered to pristine Ti control surface showed no spectral changes at any of the timepoints studied. The validity of these spectroscopic results has been confirmed using data from standard in vitro cell viability, adhesion, and proliferation assays over the same 28-day culture period. In this case, cell maturation was evidenced by the formation of natural bone apatite, which precipitated intracellularly for cells exposed to both types of HA-coated Ti at 21 and 28 days, respectively. The properties of the intracellular apatite were markedly different from that of the synthetic HA used to coat the Ti substrate with an average particle size of 230 nm, a crystalline-like shape and Ca/P ratio of 1.63 ± 0.5 as determined by SEM-EDX analysis. By comparison, the synthetic HA particles used as a control had an average size of 372 nm and were more-rounded in shape with a Ca/P ratio of 0.8 by XPS analysis and 1.28 by SEM-EDX analysis. This study shows that Raman spectroscopy can be employed to monitor single U-2 OS cell response to biomaterials that promote cell maturation towards de novo bone thereby offering a label-free in vitro testing method that allows for non-destructive analyses.

The Surface Characterisation of Fused Filament Fabricated (FFF) 3D Printed PEEK/Hydroxyapatite Composites

Polyetheretherketone (PEEK) is a high-performance thermoplastic polymer which has found increasing application in orthopaedics and has shown a lot of promise for 'made-to-measure' implants via additive manufacturing approaches. However, PEEK is bioinert and needs to undergo surface modification to make it at least osteoconductive to ensure a more rapid, improved, and stable fixation that will last longer in vivo. One approach to solving this issue is to modify PEEK with bioactive agents such as hydroxyapatite (HA). The work reported in this study demonstrates the direct 3D printing of PEEK/HA composites of up to 30 weight percent (wt%) HA using a Fused Filament Fabrication (FFF) approach. The surface characteristics and in vitro properties of the composite materials were investigated. X-ray diffraction revealed the samples to be semi-crystalline in nature, with X-ray Photoelectron Spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry revealing HA materials were available in the uppermost surface of all the 3D printed samples. In vitro testing of the samples at 7 days demonstrated that the PEEK/HA composite surfaces supported the adherence and growth of viable U-2 OS osteoblast like cells. These results demonstrate that FFF can deliver bioactive HA on the surface of PEEK bio-composites in a one-step 3D printing process.

Chemical and mechanical influence of root canal irrigation on biofilm removal from lateral morphological features of simulated root canals, dentine discs and dentinal tubules

Aim

To investigate the anti‐biofilm efficacy of irrigation using a simulated root canal model, the chemical effect of irrigants against biofilms grown on dentine discs and their impact on biofilm viscoelasticity, the efficacy of the irrigants in decontaminating infected dentinal tubules and the capacity of bacteria to regrow.

Methodology

Biofilm removal, viscoelastic analysis of remaining biofilms and bacterial viability were evaluated using a simulated root canal model with lateral morphological features, dentine discs and a dentinal tubule model, respectively. Experiments were conducted using a two‐phase irrigation protocol. Phase 1: a modified salt solution (RISA) and sodium hypochlorite (NaOCl) were used at a low flow rate to evaluate the chemical action of the irrigants. Ultrasonic activation (US) of a chemically inert solution (buffer) was used to evaluate the mechanical efficacy of irrigation. Phase 2: a final irrigation with buffer at a high flow rate was performed for all groups. Optical coherence tomography (OCT), low load compression testing (LLCT) and confocal scanning laser microscopy analysis were used in the different models. One‐way analysis of variance (anova) was performed for the OCT and LLCT analysis, whilst Kruskal–Wallis and Wilcoxon ranked tests for the dentinal tubule model.

Results

US and high flow rate removed significantly more biofilm from the artificial lateral canal. For biofilm removal from the artificial isthmus, no significant differences were found between the groups. Within‐group analysis revealed significant differences between the steps of the experiment, with the exception of NaOCl. For the dentine discs, no significant differences regarding biofilm removal and viscoelasticity were detected. In the dentinal tubule model, NaOCl exhibited the greatest anti‐biofilm efficacy.

Conclusions

The mechanical effect of irrigation is important for biofilm removal. An extra high flow irrigation rate resulted in greater biofilm removal than US in the artificial isthmus. The mechanical effect of US seemed to be more effective when the surface contact biofilm–irrigant was small. After the irrigation procedures, the remaining biofilm could survive after a 5‐day period. RISA and NaOCl seemed to alter post‐treatment remaining biofilms.

Biofilm removal from a simulated isthmus and lateral canal during syringe irrigation at various flow rates: a combined experimental and Computational Fluid Dynamics approach

Aim

(i) To quantify biofilm removal from a simulated isthmus and a lateral canal in an artificial root canal system during syringe irrigation with NaOCl at different concentrations and delivered at various flow rates (ii) to examine whether biofilm removal is further improved by a final high‐flow‐rate rinse with an inert irrigant following irrigation with NaOCl. (iii) to simulate the irrigant flow in these areas using a computer model (iv) to examine whether the irrigant velocity calculated by the computer model is correlated to biofilm removal.

Methodology

Ninety‐six artificial root canals with either a simulated isthmus or lateral canal were used. A dual‐species in vitro biofilm was formed in these areas using a Constant Depth Film Fermenter. NaOCl at various concentrations (2, 5 and 10%) or adhesion buffer (control) was delivered for 30 s by a syringe and an open‐ended needle at 0.033, 0.083, or 0.166 mL s⁻¹ or passively deposited in the main root canal (phase 1). All specimens were subsequently rinsed for 30 s with adhesion buffer at 0.166 mL s⁻¹ (phase 2). The biofilm was scanned by Optical Coherence Tomography to determine the percentage of the remaining biofilm. Results were analysed by two 3‐way mixed‐design ANOVAs (α = 0.05). A Computational Fluid Dynamics model was used to simulate the irrigant flow inside the artificial root canal system.

Results

The flow rate during phase 1 and additional irrigation during phase 2 had a significant effect on the percentage of the remaining biofilm in the isthmus (P = 0.004 and P < 0.001). Additional irrigation during phase 2 also affected the remaining biofilm in the lateral canal significantly (P ≤ 0.007) but only when preceded by irrigation at medium or high flow rate during phase 1. The effect of NaOCl concentration was not significant (P > 0.05). Irrigant velocity in the isthmus and lateral canal increased with increasing flow rate and it was substantially correlated to biofilm removal from those areas.

Conclusions

The irrigant flow rate affected biofilm removal in vitro more than NaOCl concentration. Irrigant velocity predicted by the computer model corresponded with the pattern of biofilm removal from the simulated isthmus and lateral canal.

Genome-wide analysis of H3K4me3 and H3K27me3 modifications due to Lr28 for leaf rust resistance in bread wheat (Triticum aestivum)

Present study revealed a complex relationship among histone H3 methylation (examined using H3K4/K27me3 marks), cytosine DNA methylation and differential gene expression during Lr28 mediated leaf rust resistance in wheat. During the present study, genome-wide histone modifications were examined in a pair of near isogenic lines (NILs) (with and without Lr28 in the background of cv. HD2329). The two histone marks used included H3K4me3 (an activation mark) and H3K27me3 (a repression mark). The results were compared with levels of expression (using RNA-seq) and DNA methylation (MeDIP) data obtained using the same pair of NILs. Some of the salient features of the present study include the following: (i) large scale differential binding sites (DBS) were available for only H3K4me3 in the susceptible cultivar, but for both H3K4me3 and H3K27me3 in its resistant NIL; (ii) DBSs for H3K27me3 mark were more abundant (> 80%) in intergenic regions, whereas DBSs for H3K4me3 were distributed in all genomic regions including exons, introns, intergenic, TTS (transcription termination sites) and promoters; (iii) fourteen (14) genes associated with DBSs showed co-localization for both the marks; (iv) only a small fraction (7% for H3K4me3 and 12% for H3K27me3) of genes associated with DBSs matched with the levels of gene expression inferred from RNA-seq data; (v) validation studies using qRT-PCR were conducted on 26 selected representative genes; results for only 11 genes could be validated. The proteins encoded by important genes involved in promoting infection included domains generally carried by R gene proteins such as Mlo like protein, protein kinases and purple acid phosphatase. Similarly, proteins encoded by genes involved in resistance included those carrying domains for lectin kinase, R gene, aspartyl protease, etc. Overall, the results suggest a very complex network of downstream genes that are expressed during compatible and incompatible interactions; some of the genes identified during the present study may be used in future validation studies involving RNAi/overexpression approaches.

Novel combination of non-invasive morphological and solid-state characterisation of drug-loaded core-shell electrospun fibres

In recent years, core-shell nanofibrous drug delivery systems have received increasing attention due to their ability to incorporate two or more active pharmaceutical ingredients (APIs) individually into the desired layer (either core or sheath) and thereby finely tune the release profiles of even incompatible drugs in one system. This study aims to perform formulation and solid-state characterisation of levofloxacin-loaded polylactic acid (PLA) - naproxen-sodium-loaded polyvinyl pyrrolidone (PVP) bicomponent core-shell fibrous sheets and examine the electro spinnability of the precursor combinations. The selected drugs have potential therapeutic relevance in similar systems intended for wound healing; however, in this study, they are used as model drugs to understand the physicochemical properties of a drug loaded system. In order to determine the best core- and shell-solution combination, a full factorial experimental design is used. A combination of various morphological (scanning electron microscopy and transmission electron microscopy) and microstructural characterisation techniques (X-ray photoelectron spectroscopy and Raman spectroscopy) was applied to non-invasively obtain information about the structure of the fibres and the embedded drugs. The results indicate that core-shell fibres of different compositions could be successfully prepared with various structural homogeneities. The best core-shell structure was obtained using a combination of 15% (w/w) shell concentration and 8% (w/w) PLA solution concentration. In addition to the conventional core-shell structural verification methods, the Raman spectroscopy method was implemented to reveal not only the core-shell structure of the PLA/PVP nanofibers but also the form of the embedded drugs. The Raman mapping of the fibres confirm the above results, and it is shown that an amorphous solid dispersion is formed as a result of the coaxial electrospinning process.

The influence of time and irrigant refreshment on biofilm removal from lateral morphological features of simulated root canals

Aim

To evaluate the effect of irrigant refreshment and exposure time of a 2% sodium hypochlorite solution (NaOCl) on biofilm removal from simulated lateral root canal spaces using two different flow rates.

Methodology

A dual‐species biofilm was formed by a Constant Depth Film Fermenter (CDFF) for 96 h in plug inserts with anatomical features resembling an isthmus or lateral canal‐like structures. The inserts were placed in a root canal model facing the main canal. NaOCl 2% and demineralized water (control group) were used as irrigant solutions. Both substances were applied at a flow rate of 0.05 and 0.1 mL s⁻¹. The samples were divided into three groups with zero, one or two refreshments in a total exposure time of 15 min. A three‐way analysis of variance (anova) was performed to investigate the interaction amongst the independent variables and the effect of consecutive irrigant refreshment on percentage of biofilm removal. A Tukey post hoc test was used to evaluate the effect of each independent variable on percentage biofilm removal in the absence of statistically significant interactions.

Results

For the lateral canal, NaOCl removed significantly more biofilm irrespective of the number of refreshments and exposure time (P = 0.005). There was no significant effect in biofilm removal between the consecutive irrigant refreshments measured in the same biofilm. For the isthmus, NaOCl removed significantly more biofilm irrespective of the number of refreshments and exposure time; both NaOCl and a high flow rate removed significantly more biofilm when the exposure time was analysed (P = 0.018 and P = 0.029, respectively). Evaluating the effect of consecutive irrigant refreshment on the same biofilm, 2% NaOCl, 0.1 mL s⁻¹ flow rate and one or two refreshments removed significant more biofilm (P = 0.04, 0.034 and 0.003, <0.001, respectively).

Conclusions

In this model, refreshment did not improve biofilm removal from simulated lateral root canal spaces. NaOCl removed more biofilm from the lateral canal‐ and isthmus‐like structure. A higher flow rate removed significantly more biofilm from the isthmus‐like structure. There was always remaining biofilm left after the irrigation procedures.

Human lung extracellular matrix hydrogels resemble the stiffness and viscoelasticity of native lung tissue

Chronic lung diseases such as idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD) are associated with changes in extracellular matrix (ECM) composition and abundance affecting the mechanical properties of the lung. This study aimed to generate ECM hydrogels from control, severe COPD [Global Initiative for Chronic Obstructive Lung Disease (GOLD) IV], and fibrotic human lung tissue and evaluate whether their stiffness and viscoelastic properties were reflective of native tissue. For hydrogel generation, control, COPD GOLD IV, and fibrotic human lung tissues were decellularized, lyophilized, ground into powder, porcine pepsin solubilized, buffered with PBS, and gelled at 37°C. Rheological properties from tissues and hydrogels were assessed with a low-load compression tester measuring the stiffness and viscoelastic properties in terms of a generalized Maxwell model representing phases of viscoelastic relaxation. The ECM hydrogels had a greater stress relaxation than tissues. ECM hydrogels required three Maxwell elements with slightly faster relaxation times (τ) than that of native tissue, which required four elements. The relative importance (R_i) of the first Maxwell element contributed the most in ECM hydrogels, whereas for tissue the contribution was spread over all four elements. IPF tissue had a longer-lasting fourth element with a higher R_i than the other tissues, and IPF ECM hydrogels did require a fourth Maxwell element, in contrast to all other ECM hydrogels. This study shows that hydrogels composed of native human lung ECM can be generated. Stiffness of ECM hydrogels resembled that of whole tissue, while viscoelasticity differed.

Cardiovascular complications and its relationship with functional outcomes in Guillain-Barré syndrome

BACKGROUND

Guillain-Barré syndrome (GBS) is a monophasic disease characterized by acute polyradiculoneuropathy.

AIM

This study investigated cardiovascular complications in patients with GBS and their relationship with outcomes.

DESIGN AND METHODS

We included 96 patients, who were diagnosed with GBS according to Brighton case definitions. All enrolled patients were evaluated according to a predetermined algorithm, which included nerve conduction studies, cerebrospinal fluid analysis, electrocardiography, 2D echo, cardiac markers and autonomic function testing.

RESULTS

We enrolled a total of 96 patients. The mean age of patients was 35.75 ± 17.66 years. Furthermore, 54.2% of patients developed cardiovascular complications, of which changes in electrocardiography (ECG) findings (50%), hypertension (28.12%), labile hypertension (12.5), tachycardia (26.04), bradycardia (13.54%) and a fluctuating heart rate (HR) (11.46) were common. Other cardiovascular complications seen in GBS patients were increased pro-BNP (26.04%), raised troponin T levels (3.12%), acute coronary syndrome (2.08%), heart failure (2.08%) and abnormal 2D echo findings (8.33%). The results of the univariate analysis revealed that a history of preceding infection, a Medical Research Council sum score, neck muscle weakness, facial nerve involvement, bulbar involvement, respiratory failure, cardiovascular complications, autonomic dysfunction, acute motor sensory axonal neuropathy subtype and baseline Hughes score were significantly (P < 0.005) associated with poor outcomes. However, none of these factors were found to be independently associated with poor outcomes in the multivariate analysis.

CONCLUSION

A considerable number of patients with GBS developed cardiovascular complications and it needs attention.

Role of Vascular Ultrasound in Cases of Lower Limb Hyperpigmentation

Background

Hyperpigmentation remains an important finding in cases of venous insufficiency and peripheral arterial disease (PAD) among the vascular causes.

Aims

This study aimed at finding the presence of arterial and/or venous insufficiency in patients of lower leg hyperpigmentation by using vascular ultrasound (US).

Materials and Methods

Fifty patients of lower leg pigmentation were included in the study. The detailed history, general physical examination, and laboratory investigations were done. Color Doppler ultrasonography was performed to check for venous insufficiency/PADs. Qualitative variables were correlated using chi-square test/Fisher's exact test. P < 0.05 was considered statistically significant.

Results

The mean age of the patients was 44.32 ± 14.16 years. Four patterns of skin changes were seen - reticulate macular, diffuse macular, lipodermatosclerosis and ulcer. Thirty-five (70%) patients had no visible varicose vein while 15 (30%) had visible varicose vein. In patients with visible varicose vein, color Doppler showed signs of venous insufficiency in all patients, but in cases of no visible varicose vein, color Doppler showed signs of venous insufficiency in 19 (54.28%) patients and showed no signs of venous insufficiency in others (P = 0.78). Only 1 (2%) patient showed atherosclerotic changes in both anterior tibial arteries.

Conclusion

All patients with lower leg pigmentation with or without visible varicose vein should undergo vascular US to rule out any venous insufficiency.

Brucellosis in India: results of a collaborative workshop to define One Health priorities

Brucellosis is an important zoonosis worldwide. In livestock, it frequently causes chronic disease with reproductive failures that contribute to production losses, and in humans, it causes an often-chronic febrile illness that is frequently underdiagnosed in many low- and middle-income countries, including India. India has one of the largest ruminant populations in the world, and brucellosis is endemic in the country in both humans and animals. In November 2017, the International Livestock Research Institute invited experts from government, national research institutes, universities, and different international organizations to a one-day meeting to set priorities towards a "One Health" control strategy for brucellosis in India. Using a risk prioritization exercise followed by discussions, the meeting agreed on the following priorities: collaboration (transboundary and transdisciplinary); collection of more epidemiological evidence in humans, cattle, and in small ruminants (which have been neglected in past research); Economic impact studies, including cost effectiveness of control programmes; livestock vaccination, including national facilities for securing vaccines for the cattle population; management of infected animals (with the ban on bovine slaughter, alternatives such as sanctuaries must be explored); laboratory capacities and diagnostics (quality must be assured and better rapid tests developed); and increased awareness, making farmers, health workers, and the general public more aware of risks of brucellosis and zoonoses in general. Overall, the meeting participants agreed that brucellosis control will be challenging in India, but with collaboration to address the priority areas listed here, it could be possible.

Chemical efficacy of several NaOCl concentrations on biofilms of different architecture: new insights on NaOCl working mechanisms

AIM

To investigate the anti-biofilm efficacy and working mechanism of several NaOCl concentrations on dual-species biofilms of different architecture as well as the changes induced on the architecture of the remaining biofilms.

METHODOLOGY

Streptococcus oralis J22 and Actinomyces naeslundii T14V-J1 were co-cultured under different growth conditions on saliva-coated hydroxyapatite discs. A constant-depth film fermenter (CDFF) was used to grow steady-state, four-day mature biofilms (dense architecture). Biofilms were grown under static conditions for 4 days within a confined space (less dense architecture). Twenty microlitres of buffer, 2-, 5-, and 10% NaOCl were applied statically on the biofilms for 60 s. Biofilm disruption and dissolution, as well as bubble formation, were evaluated with optical coherence tomography (OCT). The viscoelastic profile of the biofilms post-treatment was assessed with low load compression testing (LLCT). The bacteria/extracellular polysaccharide (EPS) content of the biofilms was examined through confocal laser scanning microscopy (CLSM). OCT, LLCT and CLSM data were analysed through one-way analysis of variance (ANOVA) and Tukey's HSD post-hoc test. Linear regression analysis was performed to test the correlation between bubble formation and NaOCl concentration. The level of significance was set at a < 0.05.

RESULTS

The experimental hypothesis according to which enhanced biofilm disruption, dissolution and bubble formation were anticipated with increasing NaOCl concentration was generally confirmed in both biofilm types. Distinct differences between the two biofilm types were noted with regard to NaOCl anti-biofilm efficiency as well as the effect that the several NaOCl concentrations had on the viscoelasticity profile and the bacteria/EPS content. Along with the bubble generation patterns observed, these led to the formulation of a concentration and biofilm structure-dependent theory of biofilm removal.

CONCLUSIONS

Biofilm architecture seems to be an additional determining factor of the penetration capacity of NaOCl, and consequently of its anti-biofilm efficiency.

Study of interleukin-6 and interleukin-8 levels in patients with neurological manifestations of dengue

Context:

Pro-inflammatory markers play a key role in the pathogenesis of various Flavivirus infection.

Aim:

In this study, we evaluated the role of these markers in neurological manifestations of dengue.

Settings and Designs:

Consecutive dengue cases with different neurological manifestations who presented between August 2012 and July 2014 were studied in hospital-based case–control study.

Materials and Methods:

Interleukin (IL-6) and IL-8 level were measured in serum and cerebrospinal fluid (CSF) of dengue cases with different neurological manifestations and also in age- and sex-matched controls. Level was analyzed with various parameters and outcomes.

Statistical Analysis:

Statistical analysis was done using SPSS version 16.0 by applying appropriate statistical methods. P < 0.05 considered statistically significant.

Results:

Out of the 40 enrolled cases of dengue with neurological manifestations, 29 had central nervous system and 11 had peripheral nervous system (CNS/PNS) manifestations. In CNS group, both IL-6 and IL-8 (CSF and serum) were significantly elevated (P < 0.001), whereas CSF IL-6 (P = 0.008), serum IL-6 (P = 0.001), and serum IL-8 (P = 0.005) were significantly elevated in PNS group. CSF IL-6, serum IL-6, and IL-8 were significantly elevated in poor outcome patients in CNS group (P < 0.05). CSF IL-6 and IL-8 were significantly elevated in CSF dengue positive cases as compared to CSF negative patients (P < 0.05). Cytokine level was not significantly correlated with neuroimaging abnormality in CNS group. Nine patients died and the remainder recovered.

Conclusion:

Elevated level of IL-6 and IL-8 is associated with different neurological manifestations and poor outcome, but whether they are contributing to neuropathogenesis or simply a correlate of severe disease remains to be determined.

Ophthalmological manifestation in patients of tuberculous meningitis

BACKGROUND

Vision impairment, blindness in particular is a devastating complication in patients with tuberculous meningitis. However, information regarding ophthalmological manifestation and its impact on vision is sparse in the literature. This study evaluated the spectrum of ophthalmological manifestations in tuberculous meningitis, including retinal nerve fiber layer thickness assessment by optic coherence tomography and its correlation with visual and clinical outcome.

METHODS

This was a prospective observational study done from October 2015 to March 2017. Consecutive patients of tuberculous meningitis, diagnosed as per consensus case definition were included in the study. The patients were divided into two categories: uncomplicated and complicated tuberculous meningitis. Clinical evaluation, cerebrospinal fluid examination and contrast enhanced MRI of brain was done. Detailed ophthalmological evaluation including optic coherence tomography was done in all patients. All the patients were followed for 6 months. The primary outcome was blindness or low vision after 6 months. The secondary outcome was death or severe disability after 6 months. It was defined as modified Barthel index (MBI) ≤ 12 at 6 months (including disability plus death). Appropriate statistical analysis was done.

RESULTS

Out of 101 patients of tuberculous meningitis, 47 patients of TBM belonged to uncomplicated category, while 54 patients were of complicated group. The visual impairment was present in 24 out of 101 (23.76%) patients out of which 20 (19.8%) patients had low vision while 4 (3.96%) had blindness. The visual impairment was more evident in complicated group, low vision 0.03 (1.2-31.5). The most common abnormality on fundus examination was papilledema (22.8%). The complicated group had more incidence <0.0001 (19.6-48). Optic atrophy was found in three patients while choroid tubercles were found in eight patients (all complicated TBM group). RNFL thinning was noted in 10 patients in both the eyes. On univariate analysis, presence of diplopia at baseline, impairment of color vision at baseline, visual impairment at baseline, cranial nerve VIth involvement, optic atrophy and papilledema at baseline, RNFL thinning, abnormal VEP and baseline MBI were associated with poor visual outcome. On multivariate analysis, none of the factors were found to be independently associated with poor visual outcome. On univariate analysis, many factors including baseline MRC staging, altered sensorium, seizure, hemiparesis, basal exudates, infarcts, optochiasmaticarachnoiditis, visual impairment at baseline were found to be associated with poor clinical outcome at 6 months. On multivariate analysis, presence of seizure (P = 0.047, odds ratio = 78.59, 95% confidence interval (1.07-578.72)) was the only factor found to be independently associated with poor outcome.

CONCLUSION

Wide spectrum of ophthalmological manifestation was observed in patients of tuberculous meningitis. The visual impairment was more evident in complicated tuberculous meningitis. Ophthalmological findings like optic atrophy, papilledema and RNFL thinning were associated with poor visual outcome on univariate but not multivariate analysis. Visual impairment at baseline, among other factors was associated with poor clinical outcome on univariate analysis, whereas seizure was the only factor independently associated with poor outcome on multivariate analysis.

Influence of doping ion, capping agent and pH on the fluorescence properties of zinc sulfide quantum dots: Sensing of Cu2+ and Hg2+ ions and their biocompatibility with cancer and fungal cells

Herein, a facile one-pot synthetic method was explored for the fabrication of glutathione capped Mn²⁺ doped‑zinc sulphide quantum dots (GSH-Mn²⁺-ZnS QDs) for both fluorescent detection of Cu²⁺ and Hg²⁺ ions and for fluorescence imaging of two cancer (RIN5F and MDAMB231) and fungal (Rhizopus oryzae) cells. Particularly, doping of Mn²⁺ into ZnS QDs nanocrystal structure resulted a great improvement in the fluorescence properties of ZnS QDs. The emission peak of undoped ZnS QDs was found at 447 nm, which is due to the large number of surface defects in the ZnS QDs nanostructures. Under identical conditions, there is a good linear relationship between the quenching of fluorescence intensity and analytes (Cu²⁺ and Hg²⁺ ions) concentration in the range of 0.005 to 0.2 mM and of 0.025 to 0.4 mM for Cu²⁺ and Hg²⁺ ions, respectively. The GSH-Mn²⁺-ZnS QDs exhibit least cytotoxicity against RIN5F and MDAMB231 cells, demonstrating the multifunctional applications in sensing of metal ions and biocompatibility towards cancer (RIN5F and MDAMB231) and fungal (Rhizopus oryzae) cells.

Further studies on sugar transporter (SWEET) genes in wheat (Triticum aestivum L.)

SWEET proteins represent one of the largest sugar transporter family in the plant kingdom and play crucial roles in plant development and stress responses. In the present study, a total of 108 TaSWEET genes distributed on all the 21 wheat chromosomes were identified using the latest whole genome sequence (as against 59 genes reported in an earlier report). These 108 genes included 14 of the 17 types reported in Arabidopsis and also included three novel types. Tandem duplications (22) and segmental duplications (5) played a significant role in the expansion of TaSWEET family. A number of cis-elements were also identified in the promoter regions of TaSWEET genes, indicating response of TaSWEET genes during development and also during biotic/abiotic stresses. The TaSWEET proteins carried 4-7 trans-membrane helices (TMHs) showing diversity in structure. Phylogenetic analysis using SWEET proteins of wheat and 8 other species gave four well-known clusters. Expression analysis involving both in silico and in planta indicated relatively higher expression of TaSWEET genes in water/heat sensitive and leaf rust resistant genotypes. The results provided insights into the functional role of TaSWEETs in biotic and abiotic stresses, which may further help in planning strategies to develop high yielding wheat varieties tolerant to environmental stresses.