Sol­Gel Synthesis of Manganese Doped Titanium Oxide Nanoparticles for Electrochemical Sensing of Hydroquinone.

Here we report development of a hydroquinone (HQ) electrochemical sensor using nanosized manganese doped titanium oxide as a composite material. The nanomaterial was synthesized with sol gel method using calculated amount of Mn and Ti atoms resulting into a composite metal oxide. Morphological observations indicated a uniform particle size and shape distribution with almost spherical shape and size of about 20­30 nm. While structural analysis indicated formation of mixed phase of TiO2 and MnO forming MnTiO3. The synthesized nanomaterial was used as a matrix for fabrication of hydroquinone electrochemical sensor and tested over a wide range from 2 mM to 10 mM. The developed electrochemical sensor exhibited sensitivity of 2.96 µA mM⁻¹ (23.55 µA mM⁻¹ cm⁻²) with a detection limit of 7.5 µM, which is rarely reported for such composite nanomaterial.

Investigating the impacts of treated effluent discharge on coastal water health (Visakhapatnam, SW coast of Bay of Bengal, India).

The present study investigated the impacts of treated effluent discharge on physicochemical and biological properties of coastal waters from three pharmaceuticals situated along the coast of Visakhapatnam (SW Bay of Bengal). Seawater samples were collected (during the months of December 2013, March 2014 and April 2014) from different sampling locations (Chippada (CHP), Tikkavanipalem (TKP) and Nakkapalli (NKP)) at 0- and 30-m depths within 2-km radius (0.5 km = inner, 1 km = middle and 2 km = outer sampling circles) from the marine outfall points. Physicochemical and biological parameters, which differed significantly within the stations, were likely to be influenced by strong seasonality rather than local discharge. Dissolved oxygen variability was tightly coupled with both physical and biological processes. Phytoplankton cell density and total chlorophyll (TChla) concentrations were significantly correlated with dissolved inorganic nutrient concentrations. CHP (December) represented a diatom bloom condition where the highest concentrations of diatom cells, total chlorophyll (TChla), dissolved oxygen coupled with lower zooplankton abundance and low nutrient levels were noticed. The centric diatom, Chaetoceros sp. (> 50%) dominated the phytoplankton community. TKP (March) represented a post-diatom bloom phase with the dominance of Pseudo-nitzschia seriata; zooplankton abundance and nutrient concentrations were minimum. Conversely, NKP (April) represented a warm well-stratified heterotrophic period with maximum zooplankton and minimum phytoplankton density. Dinoflagellate abundance increased at this station. Relatively higher water temperature, salinity, inorganic nutrients coupled with very low concentrations of dissolved oxygen, TChla and pH were observed at this station. Copepods dominated the zooplankton communities in all stations and showed their highest abundance in the innermost sampling circles. Treated effluent discharge did not seem to have any significant impact at these discharge points.

Evaluation of surface water and sediment quality in Chicalim Bay, Nerul Creek, and Chapora Bay from Goa coast, India-a statistical approach.

To better understand the spatial and temporal variation in surface water and sediment quality, parameters were evaluated from the three sites Chicalim Bay (CB), Nerul Creek (NC), and Chapora Bay (ChB) along the Goa coast, which has major oyster beds. Multivariate analysis such as cluster analysis (CA), Box-Whisker plot (Box plot), and principle component analysis (PCA) revealed that nitrate (NO3-N), nitrite (NO2-N), phosphate (PO4-P), particulate organic carbon (POC), total suspended solids (TSS), dissolved oxygen (DO), and phaeopigments are the responsible parameters for spatio-temporal variability among the studied sites. Results showed an elevated level of ecotoxicological hazard at CB while moderate toxicological risks were observed for organisms at NC. In contrast, ChB was considerably pristine compared with other two sampling sites. Results of present study showed marked dominance of nutrients, phaeopigments, POC, and TSS at CB and NC. The increased levels of these parameters are attributed to the anthropogenic activities which may cause potential risk to humans via consumption of oysters. Therefore, we suggest monitoring heavy metal concentrations in tissue of commercially important oyster species, and their ambient environment (water and sediment) from these estuaries is necessary to create a comprehensive pollution database.

Vitamin D replacement therapy in patients with cardiac syndrome X.

AIMS: The aim of present study was to assess whether vitamin D, with proven beneficial effects on the cardiovascular system, has any effect on angina and exercise-induced ischemia in patients with cardiac syndrome X and low serum vitamin D. METHODS: Patients with cardiac syndrome X and low serum vitamin D3 were studied before and after treatment with an intramuscular injection of vitamin D3 (300,000 units, every other week for 2 months). We determined the angina episode (per day) and several indices of exercise capacity. RESULTS: At the end of the treatment course (75±6 day), a significant increase of serum vitamin D3 occurred and was within the normal range (45±8 ng/ml) and the frequency of angina improved significantly (p=0.003). Exercise duration and maximal work capacity increased significantly (p<0.001). Maximal ST-segment depression (mm) decreased significantly (p=0.001). The calculated Duck treadmill score improved significantly (p=0.001). CONCLUSIONS: Our findings show that vitamin D replacement therapy in patients with cardiac syndrome X and vitamin D deficiency dramatically improves symptoms and signs of ischemia.

New insights into APCVD grown monolayer MoS2 using time-domain terahertz spectroscopy.

In modern era, wireless communications at ultrafast speed are need of the hour and search for its solution through cutting edge sciences is a new perspective. To address this issue, the data rates in order of terabits per second (TBPS) could be a key step for the realization of emerging sixth generation (6G) networks utilizing terahertz (THz) frequency regime. In this context, new class of transition metal dichalcogenides (TMDs) have been introduced as potential candidates for future generation wireless THz technology. Herein, a strategy has been adopted to synthesize high-quality monolayer of molybdenum di-sulfide (MoS2) using indigenously developed atmospheric pressure chemical vapor deposition (APCVD) set-up. Further, the time-domain transmission and sheet conductivity were studied as well as a plausible mechanism of terahertz response for monolayer MoS2 has been proposed and compared with bulk MoS2. Hence, the obtained results set a stepping stone to employ the monolayer MoS2 as potential quantum materials benefitting the next generation terahertz communication devices.

Interaction of polyethyleneimine-functionalized ZnO nanoparticles with bovine serum albumin.

In biological fluids, nanoparticles are always surrounded by proteins. As the protein is adsorbed on the surface, the extent of adsorption and the effect on the protein conformation and stability are dependent on the chemical nature, shape, and size of the nanoparticle (NP). We have carried out a detailed investigation on the interaction of bovine serum albumin (BSA) with polyethyleneimine-functionalized ZnO nanoparticles (ZnO-PEI). ZnO-PEI was synthesized using a wet chemical method with a core size of ~3-7 nm (from transmission electron microscopy). The interaction of BSA with ZnO-PEI was examined using a combination of calorimetric, spectroscopic, and computational techniques. The binding was studied by ITC (isothermal titration calorimetry), and the result revealed that the complexation is enthalpy-driven, indicating the possible involvement of electrostatic interaction. To investigate the nature of the interaction and the location of the binding site, a detailed domain-wise surface electrostatic potential calculation was performed using adaptive Poisson-Boltzmann software (APBS). The result shows that the protein surface can bind the nanoparticle. On binding ZnO-PEI, the protein gets destabilized to some extent, as displayed by CD (circular dichroism) and FTIR (Fourier transform infrared) spectroscopy. Chemical and thermal denaturation of BSA, when carried out in the presence of ZnO-PEI, also indicated a small perturbation in the protein structure. A comparison of the enthalpy and entropy components of binding with those derived for the interaction of BSA with ZnO nanoparticles explains the effect of hydrophilic cationic species attached on the NP surface. The effect of the NP surface modification on the structure and stability of BSA would find useful applications in nanobiotechnology.

One-pot synthesis and characterization of Nb2O5 nanopowder.

Nanosized niobium oxide powders were synthesized with a yield of approximately 87% using a simple and facile soft-chemical process. Niobium pentachloride (Nb2Cl5) was used as the precursor which was first converted into niobium ethoxide and then hydrolysed with water to synthesize niobia nanopowder. The synthesized powder was calcined at 500 degrees C for phase conversion to end-centered monoclinic as confirmed by diffraction studies and elemental analysis with a chemical composition in the ratio of Nb:O as 1:2.5. The molecular framework of Nb-O-Nb stretching and asymmetric frequency was confirmed by FT-IR, UV-visible and Raman spectroscopic studies. The size, shape and surface morphology of the powders were observed by SEM and TEM which indicated particle sizes of approximately 20 nm. The surface area of 20 m2/g, pore volume of 0.0538 cm2/g and the average pore size of 6.5 nm2 for the calcined sample were obtained with the help of nitrogen adsorption/desorption method using the Barrett-Joyner-Halenda (BJH) method which indicates that the synthesized powder can be used for catalysis and other surface sensitive applications.

Understanding the effect of flower extracts on the photoconducting properties of nanostructured TiO2.

Here we report an easy method to improve the optoelectronic properties of commercially available TiO2 nanopowder using extracts of various flowers viz. Calendula Orange (CO), Calendula Yellow (CY), Dahlia Violet (DV), Dahlia Yellow (DY), Rabbit flower (RF), Sweet Poppy (SP), Sweet Williams (SW) and their Mixed Extracts (ME). Various analysis techniques such as UV-Vis, FTIR, FESEM, XRD, and Raman spectroscopy were used to characterize for elemental, structural and morphological properties of the unmixed/mixed TiO2 nanopowder. TiO2 nanopowder was also calcined at 550 degrees C. Thick films of the these unmixed/mixed powder were printed, using conventional screen printing method, on fluorine doped tin oxide (FTO) substrate with organic binders and dried at 45 degrees C. The photoconducting properties are investigated as a function of wavelength from ultra-violet (UV) to infra-red (IR) region at a constant illumination intensity. Photocurrent gradually decreases when irradiated from UV to IR region. In case of unmixed and uncalcined TiO2, conductance decreased continuously whereas when extracts are added, a flat region of conductance is observed. The overall effect of extracts (colour pigments) is seen as an increase in the photoconductance. Highest photoconductance is observed in case of DY flower extract. Anthocyanins, present in flowers are known to have antioxidative properties and hence can contribute in photoconduction by reducing the surface adsorbed oxygen. This investigation indicates the potential use of flower extracts for dye sensitized solar cell (DSSC).

Photoconducting properties of a unit nanostructure of ZnO assembled between microelectrodes.

The photoconducting properties of a unit microflower of zinc oxide are investigated as a function of wavelength from UV to IR region at constant illumination intensity. Synthesized flowers were trapped in 2 microm gap, between pre-prepared gold microelectrodes, using AC dielectrophoresis. Photocurrent drastically increases upon illumination in the UV region, whereas it gradually reduces when irradiated in visible and IR region. Higher photoconductivity in UV region is correlated to band to band transition upon illumination. In visible region, deep level transitions are expected which intern exhibits comparatively low photocurrent. Photoconduction in IR region is only due to the adsorbed surface oxygen species. This investigation suggests the potential application of ZnO nanostructures for various optoelectronic device applications.

Evaluation of dietary stevioside supplementation on anti-human serum albumin immunoglobulin G, Alpha-1-glycoprotein, body weight and thyroid hormones in broiler chickens.

Sixty male broiler chickens fed a diet supplemented with 130 mg/kg stevioside (S group) or an unsupplemented diet (C group) from day 1 of age onwards. On day 21 of age, ten birds from either the S (SH) or C (CH) group were injected subcutaneously with 100 µg human serum albumin (HSA) and ten others from either S (SP) or C (CP) group injected with 100 µl phosphate-buffered saline (PBS) in the same way. There were no significant effect of supplementation nor interaction with age on average body weights, T(3) and T(4) concentrations of non-injected chickens. After the primary immunization, α(1) -glycoprotein concentrations increased in all treatment groups except the CP group, and were significantly higher in the CH group in relation to the other groups. Fourteen and 18 days after the primary immunization, HSA injected chickens of both dietary treatments had significantly higher anti-HSA immunoglobulin G (IgG) levels than their PBS injected controls. No effect of stevioside supplementation was observed for IgG level. In conclusion, dietary stevioside inclusion can attenuate the pro-inflammatory response after stimulation of the innate immune response in broiler chickens.

Contrasting effect of gold nanoparticles and nanorods with different surface modifications on the structure and activity of bovine serum albumin.

Nanoparticles exposed to biofluids become coated with proteins, thus making protein-nanoparticle interactions of particular interest. The consequence on protein conformation and activity depends upon the extent of protein adsorption on the nanoparticle surface. We report the interaction of bovine serum albumin (BSA) with gold nanostructures, particularly gold nanoparticles (GNP) and gold nanorods (GNR). The difference in the geometry and surface properties of nanoparticles is manifested during complexation in terms of different binding modes, structural changes, thermodynamic parameters, and the activity of proteins. BSA is found to retain native-like structure and properties upon enthalpy-driven BSA-GNP complexation. On the contrary, the entropically favored BSA-GNR complexation leads to substantial loss in protein secondary and tertiary structures with the release of a large amount of bound water, as indicated by isothermal calorimetry (ITC), circular dichroism (CD), and Fourier transform infrared (FTIR) and fluorescence spectroscopies. The esterase activity assay demonstrated a greater loss in BSA activity after complexation with GNR, whereas the original activity is retained in the presence of GNP. The formation of large assemblies (aggregates) and reduced average lifetime, as evidenced from dynamic light scattering and fluorescence decay measurements, respectively, suggest that GNR induces protein unfolding at its surface. The effect of temperature on the CD spectra of BSA-GNP was found to be similar to that of pristine BSA, whereas BSA-GNR shows distortion in CD spectra at lower wavelengths, strengthening the perception of protein unfolding. High binding constant and entropy change for BSA-GNR complexation determined by ITC are consistent with large surfacial interaction that may lead to protein unfolding. The present work highlights the differential response of a protein depending on the nature of the nanostructure and its surface chemistry, which need to be modulated for controlling the biological responses of nanostructures for their potential biomedical applications.

Morphological variations and structural properties of ZnO nanostructures grown by rapid thermal CVD.

Various nanostructures of ZnO such as nanowires, sea urchin like and nano needles were grown using rapid thermal chemical vapor deposition technique (RTCVD), in oxygen ambient. For the growth of such structures, oxygen pressure was kept as 0.1 Torr whereas the chamber base pressure was 10(-5) Torr. The growth temperature was varied from 600 degrees C to 850 degrees C, which resulted in morphological variations. X-ray diffraction measurement revealed the hexagonal wurtzite structure of ZnO preferably oriented in [001] direction, which was further confirmed by high-resolution transmission electron microscopic (HRTEM) observations. X-ray photoelectron spectroscopy (XPS) analysis suggests the presence of Zn 2p and O 1s. Raman E2 high peaks at approximately 434 cm(-1) has the highest intensity compared to other modes supports XRD results. Presence of low E2 peaks at approximately 330 cm(-1) indicates defects and oxygen vacancies.

Urea sensing characteristics of titanate nanotubes deposited by electrophoretic deposition method.

Urea sensing properties of titanate nanotubes (TNT) are presented here. TNT films were deposited by electrophoretic deposition (EPD) method on aluminum substrate. Prior to EPD, commercial nanoparticles of TiO2 were hydrothermally treated at 70 degrees C for 48 h after sonicating the solution for 8 h. Hydrothermal method resulted in the conversion of particles to tubular structure following the established method. Urease was covalently attached with TNT (by soaking in urease solution for 3 h). In general, conductivity of film increases after urease immobilization. The urease immobilized films were characterized for urea sensing in the concentration range of 1 mM to 500 mM. Three different sensitivity regions are observed viz. (i) lower concentrations (below 10 mM); (ii) linear region up to 100 mM and a (iii) saturation region above 100 mM. Sensors are extremely sensitive in region (i). From the elemental analyses of the films after urease immobilization, urease was found attached with TiO2, as evident by N 1s peak in the photoelectron spectra. Cyclic voltammetric studies indicated surface-confined redox couple is responsible for sensing behavior. A possible sensing mechanism is presented and discussed.

Femtosecond powder diffraction with a laser-driven hard X-ray source.

X-ray powder diffraction with a femtosecond time resolution is introduced to map ultrafast structural dynamics of polycrystalline condensed matter. Our pump-probe approach is based on photoexcitation of a powder sample with a femtosecond optical pulse and probing changes of its structure by diffracting a hard X-ray pulse generated in a laser-driven plasma source. We discuss the key aspects of this scheme including an analysis of detection sensitivity and angular resolution. Applying this technique to the prototype molecular material ammonium sulfate, up to 20 powder diffraction rings are recorded simultaneously with a time resolution of 100 fs. We describe how to derive transient charge density maps of the material from the extensive set of diffraction data in a quantitative way.

Role of surface adsorbed anionic species in antibacterial activity of ZnO quantum dots against Escherichia coli.

We have studied the role of surface bound anionic species on zinc oxide (ZnO) quantum dots (QDs) for the antibacterial activity against Escherichia coli (E. coli) bacteria. The ZnO QDs with surface adsorbed anionic species of acetate ions and nitrate ions have been synthesized using wet chemical route. X-Ray diffraction studies reveal single-phase hexagonal wurtzite structure of as synthesized ZnO QDs. The particle size was found to be 3-5 nm for acetate adsorbed ZnO QDs and 4-7 nm for nitrate adsorbed ZnO QDs. Minimum inhibitory concentration (MIC) measurements and growth kinetics studies for E-coli show a marked difference in the antibacterial activity of ZnO QDs with both anionic species. The MIC for acetate adsorbed ZnO QDs was found to be 2.5 mM in light and 3 mM in dark. However, nitrate adsorbed ZnO QDs exhibits MIC about 6 mM in light and no significant bacterial growth inhibition was observed upto 30 mM under dark. The enhanced bacterial growth inhibition observed for acetate adsorbed ZnO QDs is attributed to the inherent ability of acetate ions to generate reactive oxygen species. The acetate adsorbed QDs having excellent antibacterial activities suggests its potential application for practical bactericidal realization.

Glucose sensor based on nano-baskets of tin oxide templated in porous alumina by plasma enhanced CVD.

A feasibility study of glucose oxidase (GOx) immobilized tin oxide thin films, consisting of nano-baskets, for glucose sensing is presented. The nano-baskets of SnO(2) were grown on in-house fabricated anodized aluminum oxide pores of approximately 80-nm diameter using plasma enhanced chemical vapor deposition (PECVD) at an RF power of 60W. Hydrated stannic chloride was used as a precursor and O(2) (20 sccm) as a reactant gas. The deposition was carried out from 350 to 450 degrees C at a pressure of 0.2 Torr for 15 min each. Deposition at 450 degrees C resulted in crystalline film with basket-like (nano-sized) structure. GOx was immobilized by physical adsorption (soaking films in GOx solution containing 1000 units for 3h). Increase in film conductivity was noticed after GOx immobilization. The immobilized films were found sensitive to glucose (C(2)H(12)O(6), dextrose) concentration from 10 to 360 mg/dl. Sensitivity increases linearly with glucose concentration. Nano-baskets resulted in higher sensitivity in comparison with other structures. From the elemental analyses of the films after GOx immobilization, GOx was found covalently attached with tin oxide, as evident by N 1s peak in the photoelectron spectra. A possible sensing mechanism is presented and discussed.

Application of pristine and doped SnO2 nanoparticles as a matrix for agro-hazardous material (organophosphate) detection.

With an increasing focus on applied research, series of single/composite materials are being investigated for device development to detect several hazardous, dangerous, and toxic molecules. Here, we report a preliminary attempt of an electrochemical sensor fabricated using pristine Ni and Cr-doped nano tin oxide material (SnO2) as a tool to detect agro-hazardous material, i.e. Organophosphate (OP, chlorpyrifos). The nanomaterial was synthesized using the solution method. Nickel and chromium were used as dopant during synthesis. The synthesized material was calcined at 1000 °C and characterized for morphological, structural, and elemental analysis that showed the formation of agglomerated nanosized particles of crystalline nature. Screen-printed films of powder obtained were used as a matrix for working electrodes in a cyclic voltammogram (CV) at various concentrations of organophosphates (0.01 to 100 ppm). The CV curves were obtained before and after the immobilization of acetylcholinesterase (AChE) on the nanomaterial matrix. An interference study was also conducted with hydroquinone to ascertain the selectivity. The preliminary study indicated that such material can be used as suitable matrix for a device that can easily detect OP to a level of 10 ppb and thus contributes to progress in terms of desired device technology for the food and agricultural-industries.

A Highly-Sensitive Picric Acid Chemical Sensor Based on ZnO Nanopeanuts.

Herein, we report a facile synthesis, characterization, and electrochemical sensing application of ZnO nanopeanuts synthesized by a simple aqueous solution process and characterized by various techniques in order to confirm the compositional, morphological, structural, crystalline phase, and optical properties of the synthesized material. The detailed characterizations revealed that the synthesized material possesses a peanut-shaped morphology, dense growth, and a wurtzite hexagonal phase along with good crystal and optical properties. Further, to ascertain the useful properties of the synthesized ZnO nanopeanut as an excellent electron mediator, electrochemical sensors were fabricated based on the form of a screen printed electrode (SPE). Electrochemical and current-voltage characteristics were studied for the determination of picric acid sensing characteristics. The electrochemical sensor fabricated based on the SPE technique exhibited a reproducible and reliable sensitivity of ~1.2 µA/mM (9.23 µA·mM-1·cm-2), a lower limit of detection at 7.8 µM, a regression coefficient (R²) of 0.94, and good linearity over the 0.0078 mM to 10.0 mM concentration range. In addition, the sensor response was also tested using simple I-V techniques, wherein a sensitivity of 493.64 µA·mM-1·cm-2, an experimental Limit of detection (LOD) of 0.125 mM, and a linear dynamic range (LDR) of 1.0 mM-5.0 mM were observed for the fabricated picric acid sensor.

Ecotoxicological effect of grounded MV River Princess on the intertidal benthic organisms off Goa.

The ecotoxicological effects of oil spill from the grounded vessel MV River Princess on the intertidal benthic organisms of Sinquerim-Candolim beach at Goa were investigated. An intertidal expanse of 1 km on either side of the grounded vessel was selected to evaluate the concentration of total petroleum hydrocarbon (TPH) in the sediment and its effects on the composition, abundance and diversity of micro-, meio- and macrobenthos. TPH in the intertidal sediment ranged from 7.8 to 89 microg g(-1) (mean 35.44+/-26.35 SD). Microbenthos comprised of microalgae, protozoans and juvenile forms of meiobenthos. Apart from juvenile nematodes, which were abundant, Coscinodiscus spp., Navicula spp., and Nitzschia spp. representing microalgae were also observed in microbenthic samples. Meiobenthos was represented by 13 taxa and their total density ranged between 92 and 1057 nos. 10 cm(-2). Maximum meiobenthic abundance of 1057 nos. 10 cm(-2) was observed at Sinquerim. Nematodes were the dominant meiobenthic taxa followed by turbellarians and harpacticoid copepods. The macrobenthos was numerically dominated by polychaetes, followed by crustaceans whereas bivalve molluscs were less represented. There was substantial increase in the petroleum concentration in the beach sediment compared to the previously reported values and highest TPH (89 microg g(-1) sediment) values were in the vicinity of the grounded vessel. The polychaete/amphipod ratio and cumulative and partial dominance abundance-biomass curves showed significant negative impact of TPH on macrofauna. The benthic community structure also showed measurable changes, as there was significant decrease (60%) in the number of species. Given that the microalgal counts were low in sediment, it is assumed that the intertidal meiofauna was possibly using oil-degrading bacteria as alternate food source. In conclusion, the results reported here suggest that the grounded ore carrier is not only detrimental to the beach community, that may take longer time for recovery, but also affects the beach morphology which may have long-term impact on local fishery.

Homocysteine and Mild Cognitive Impairment: Are These the Tools for Early Intervention in the Dementia Spectrum?

Dementia, being a neurodegenerative disease, has devastating consequences not just for the ailing but also for the carers as it has a tremendous negative impact on the quality of life. The pathophysiology of dementia commences far earlier than its diagnosis. Mild cognitive impairment (MCI) is a stage prior to definite dementia. The progression from MCI to dementia is insidious with no definite demarcation, thus making diagnosis clinically difficult at an early stage. This paper attempts to throw light on the epidemiology, risk factors and the aetiopathogenesis of MCI. It further attempts to elaborate on the rate of conversion of MCI to definite dementia and the factors influencing the same. Many established as well as probable, modifiable as well as non-modifiable risk factors influence the progress of MCI to definite dementia. Homocysteine, a sulphur containing amino-acid has been identified as a probable risk factor for the dementia spectrum. Various existing clinical evidences and biological plausibility towards probable link between homocysteine and dementia are discussed in this paper. B vitamin mediated homocysteine reduction and cognitive outcomes demonstrate mixed results. This review attempts to evaluate hyperhomocysteinaemia and MCI as a brain risk marker and assess their potential for future research with a view to attempt early intervention.