Ultrasound Needle Guidance System for Precision Vaccinations and Drug Deliver

Image-guided needles are currently used for drug delivery in bodies, but the additional time associated with aligning and maintaining the needle’s position results in increased patient discomfort or risk of invasion of the human body. In this paper, a needle guidance system using piezoelectric materials is designed and analyzed for precise drug delivery without damaging parts of the body and improving processing time. A piezoelectric generates an ultrasound wave that can propagate through different mediums, and a second piezoelectric crystal can receive that energy and convert it into voltage. A 1D real-time image represents the changes of the voltage induced in the double piezoelectric crystal. Extensive data analysis and visualization are done using different obstacles and location of the needle verified for other mediums. The presence of obstacles in between those crystals can be identified in the real-time grayscale image. The needle can reach its destination using this image information as directional guidance. This guided drug delivery improves patient recovery time and eliminates extra injuries that can be caused due to wrong needle injections, such as lumbar puncture-related nerve damage.

Characterizing the influence of tide on the physico-chemical parameters and nutrient variability in the coastal surface water of the northern Bay of Bengal during the winter season

The spatial distribution of physico-chemical parameters（sea surface temperature（SST）, p H, sea surface salinity（SSS）, dissolved oxygen（DO） and Secchi depth） along with filterable nutrients（dissolved inorganic nitrate（DIN）,dissolved inorganic phosphate（DIP） and reactive silicate（DSi）） are measured in the winter months of November,December, January and February for four consecutive years from 2009–2010 to 2012–2013 on the shallow continental shelf（〈20 m bathymetry） of the coastal waters（up to 18 km away from shoreline） of the northern Bay of Bengal（n Bo B） during the highest high tide（HHT） and lowest low tide（LLT） hours for the first time. The variability of the coastal biogeochemical environment is assessed during the HHT and LLT hours and for this purpose, seawater samples are collected from seven different locations of a transect in the coastal region. Physicochemical parameters（except SST） show significant difference in magnitude during the HHT and LLT hours respectively. p H, SSS and DO are found to increase in the HHT hours and vice-versa. The data reveal that during the LLT hours, a relative increase of freshwater input in the n Bo B can have elevated the nutrient concentration compared with that observed during the HHT hours. The ratio of nutrient concentration is found to deviate significantly from the Redfield ratio. The abundance of DIP is much higher compared with that of DIN and DSi.The anthropogenic sources of DIP from the upstream flow（especially the domestic effluent of several metropolises） can be mainly attributed behind such an observation. In order to characterize and establish the trend of such variation in such an important bio-climatic region, long-term and systematic ecosystem monitoring in the coastal water of the n Bo B northern Bay of Bengal should be carried out throughout the year.

A multi-purpose National Forest Inventory in Bangladesh:design,operationalisation and key results

Background:National forest inventory and forest monitoring systems are more important than ever considering continued global degradation of trees and forests.These systems are especially important in a country like Bangladesh,which is characterised by a large population density,climate change vulnerability and dependence on natural resources.With the aim of supporting the Government’s actions towards sustainable forest management through reliable information,the Bangladesh Forest Inventory(BFI)was designed and implemented through three components:biophysical inventory,socio-economic survey and remote sensing-based land cover mapping.This article documents the approach undertaken by the Forest Department under the Ministry of Environment,Forests and Climate Change to establish the BFI as a multipurpose,efficient,accurate and replicable national forest assessment.The design,operationalization and some key results of the process are presented.Methods:The BFI takes advantage of the latest and most well-accepted technological and methodological approaches.Importantly,it was designed through a collaborative process which drew from the experience and knowledge of multiple national and international entities.Overall,1781 field plots were visited,6400 households were surveyed,and a national land cover map for the year 2015 was produced.Innovative technological enhancements include a semi-automated segmentation approach for developing the wall-to-wall land cover map,an object-based national land characterisation system,consistent estimates between sample-based and mapped land cover areas,use of mobile apps for tree species identification and data collection,and use of differential global positioning system for referencing plot centres.Results:Seven criteria,and multiple associated indicators,were developed for monitoring progress towards sustainable forest management goals,informing management decisions,and national and international reporting needs.A wide range of biophysical and socioeconomic data were collected,and in some cases integrated,for estimating the indicators.Conclusions:The BFI is a new information source tool for helping guide Bangladesh towards a sustainable future.Reliable information on the status of tree and forest resources,as well as land use,empowers evidence-based decision making across multiple stakeholders and at different levels for protecting natural resources.The integrated socioeconomic data collected provides information about the interactions between people and their tree and forest resources,and the valuation of ecosystem services.The BFI is designed to be a permanent assessment of these resources,and future data collection will enable monitoring of trends against the current baseline.However,additional institutional support as well as continuation of collaboration among national partners is crucial for sustaining the BFI process in future.

Biocompatible silver nanoparticles: An investigation into their protein binding efficacies, anti-bacterial effects and cell cytotoxicity studies

Green synthesis of silver nanoparticles(AgNPs)has garnered tremendous interest as conventional methods include the use and production of toxic chemicals,products,by-products and reagents.In this regard,the synthesis of AgNPs using green tea(GT)extract and two of its components,(-)-epigallocatechin gallate(EGCG)and(+)-catechin(Ct)as capping/stabilizing agents,is reported.The synthesized AgNPs showed antibacterial activity against the bacterial strains Staphylococcus aureus and Escherichia coli,along with anticancer activity against HeLa cells.After administering nanoparticles to the body,they come in contact with proteins and results in the formation of a protein corona;hence we studied the interactions of these biocompatible AgNPs with hen egg white lysozyme(HEWL)as a carrier protein.Static quenching mechanism was accountable for the quenching of HEWL fluorescence by the AgNPs.The binding constant(Kb)was found to be higher for EGCG-AgNPs((2.309±0.018)×104 M-1)than for GT-AgNPs and Ct-AgNPs towards HEWL.EGCG-AgNPs increased the polarity near the binding site while Ct-AgNPs caused the opposite effect,but GT-AgNPs had no such observable effects.Circular dichroism studies indicated that the AgNPs had no such appreciable impact on the secondary structure of HEWL.The key findings of this research included the synthesis of AgNPs using GT extract and its constituent polyphenols,and showed significant antibacterial,anticancer and protein-binding properties.The-OH groups of the polyphenols drive the in situ capping/stabilization of the AgNPs during synthesis,which might offer new opportunities having implications for nanomedicine and nanodiagnostics.

Tree assemblages and diversity patterns in Tropical Juri Forest,Bangladesh

Juri is a biodiversity-rich primary forest in Bangladesh, which remains ecologically unexplored. We identified tree species and examined the richness, alpha（a）diversity and floristic similarity patterns within the identified communities. Vegetation and environmental data were sampled in 120（0.04 ha） study plots. Tree communities were delimited by two-way indicator species analysis（TWINSPAN）. In total, 78 tree species of 35 families and58 genera were identified. TWINSPAN identified six tree communities： A—Tricalysia singularis; B—Kydia calycina-Castanopsis tribuloides; C—Polyalthia simiarum-Duabanga grandiflora; D—Ficus roxburghii; E—Artocarpus lacucha; F—Artocarpus lacucha. Mean richness, Shannon and Gini-Simpson indices were highest for the Polyalthia simiarum-Duabanga grandiflora community, while Ficus roxburghii showed lowest diversity. Significant differences（p = 0.05） in three diversity indices were recorded between Polyalthia simiarum-Duabanga grandiflora and Ficus roxburghii. Tree compositional similarity was greatest between Kydia calycina-Castanopsis tribuloides and Polyalthia simiarum-Duabanga grandiflora（0.712）.

Superfluid density dominated junction resistance of bulk polycrystalline YBa_(2)Cu_(3)O_(7−δ) and DyBa_(2)Cu_(3)O_(7−δ) superconductors at low temperature

Resistances of grain junctions of bulk polycrystalline YBa_(2)Cu_(3)O_(7−δ)(YBCO) and DyBa_(2)Cu_(3)O_(7−δ)(DyBCO) superconductors have been extracted following(i)Ambegaokar‐Baratoff(AB)and(ii)de Gennes(dG)equations.Current–voltage(IV)below the critical temperature(T_(c))has been used to extract transport critical current density(J_(c)).The variations of the junction resistances,(RN)with temperature(T)exhibit that below a critical value of the normalised superfluid density(NSD),junctions become very low resistive and exhibit metallicity.Dependence of this feature of RN on the energy gaps has also been explored.Weak scattering limit is found to be compatible with the maximum of RN(T)as is observed from the corresponding NSD.