Porous, n-p type ultra-long, ZnO@Bi2O3 heterojunction nanorods - based NO2 gas sensor: new insights towards charge transport characteristics.

Herein, porous 1D n-p type ultra-long ZnO@Bi2O3 heterojunction nanorods have been synthesized by a solvothermal method and their complex charge transport characteristics pertaining to NO2 gas sensing properties have been investigated. The porous structure of the ZnO@Bi2O3 heterojunction nanorods assisted in achieving superior sensing properties compared to pristine ZnO nanorods. Temperature-dependent in situ electrical studies of the porous heterojunction nanorods explored the unique electron transport properties under different environments, which revealed the accumulation/depletion of electrons and charge carrier recombination leading to band bending at the metal oxide heterojunctions. The formation of electron depletion layers at n-ZnO/p-Bi2O3 interfaces is believed to increase the adsorption of oxidizing gas, resulting in a fast response time (10-12 s) and 10 times higher sensitivity than that of the ZnO nanorod-based sensor towards 500 ppb NO2. To study the structure-property correlation of the ultra-long ZnO@Bi2O3 heterojunction nanorods-based sensor, a crystallographic model supported by transmission electron microscopy analysis was adopted to understand the NO2 gas adsorption properties on the surface. The crystallographic model helps to visualize the dangling bonds and the ratio of metal to oxygen ions present at the exposed crystal planes. The results suggest that porous, ultralong n-p type ZnO@Bi2O3 heterojunction nanorods could be a promising candidate for a high performance NO2 sensor for real time applications.

Enhancement of drug permeability across blood brain barrier using nanoparticles in meningitis.

The central nervous system, one of the most delicate microenvironments of the body, is protected by the blood-brain barrier regulating its homeostasis. Blood-brain barrier is a highly complex structure that tightly regulates the movement of ions of a limited number of small molecules and of an even more restricted number of macromolecules from the blood to the brain, protecting it from injuries and diseases. However, the blood-brain barrier also significantly precludes the delivery of drugs to the brain, thus, preventing the therapy of a number of neurological disorders. As a consequence, several strategies are currently being sought after to enhance the delivery of drugs across the blood-brain barrier. Within this review a brief description of the structural and physiological features of the barriers and the recently born strategy of brain drug delivery based on the use of nanoparticles are described. Finally, the future technological approaches are described. The strong efforts to allow the translation from preclinical to concrete clinical applications are worth the economic investments.

Smokeless Tobacco-associated Lesions: A Mobile Health Approach.

AIM: Globally, India accounts for the highest number of oral cancer cases. The survival rates are about 30% lower than those in developing countries. The main reason for these dismal figures is the late presentation of patients. In order to downstage oral cancer in such a scenario, screening and diagnosis at an early stage is warranted. A pragmatic approach is needed for an oral cancer screening program, hence a mobile health (mHealth) approach was used. In this approach, health workers were empowered with mobile phones with decision-based algorithm. Risk stratification of tobacco habit enables us to identify lesions associated with particular habits. MATERIALS AND METHODS: A specific cohort of factory employees who predominantly had pure tobacco chewing habit was chosen to examine the effect of pure tobacco on oral mucosa. One thousand three hundred and fifty-seven subjects were screened in two phases. In the first phase, habits and oral lesions were identified and photographed. The photographs were remotely diagnosed by an oral medicine specialist and those subjects requiring biopsy were recalled for phase II. Cytology and biopsy were performed in phase II. RESULTS: The predominant habit was smokeless tobacco (SLT), in 582 subjects. The most commonly encountered lesion was tobacco pouch keratosis seen in 397 subjects. Biopsy was performed for 71 subjects, most cases showed hyperkeratosis and mild dysplasia. One subject had moderate dysplasia. CONCLUSION: There was minimal alteration of tissues in our study subjects, which can be considered as low-risk. Use of mHealth empowered frontline healthcare workers to identify subjects with lesions and enabled remote diagnosis by specialist in resource-constrained settings. CLINICAL SIGNIFICANCE: Use of mHealth enabled us have an electronic record of subject details. This data shall be used for a planned follow-up of the same cohort after 3 years.

Dimensional measurement accuracy of 3-dimensional models from cone beam computed tomography using different voxel sizes.

OBJECTIVES: To compare the geometric accuracy and measurement reliability of 3-dimensional (3D) reconstructed models of the mandible created from cone beam computed tomography (CBCT) images obtained with 0.2-mm and 0.4-mm voxel sizes with the reference standard model and compare the accuracy of the CBCT-based models to each other. STUDY DESIGN: The reference standard 3D model of a dry human mandible was obtained using a white light scanner. The mandible was scanned with CBCT 10 times at each voxel size. The models created from the CBCT data were compared with the reference standard by using a point-based rigid registration algorithm where the distance differences between the superimposed CBCT models and the reference standard model were recorded. The measurements derived from the 2 CBCT-based scans were also compared. RESULTS: Mean deviations from the reference standard for 0.2-mm and 0.4-mm voxel scans were 0.4342 mm and 0.4580 mm, respectively (P ≥ .16). The CBCT scans with both 0.2-mm and 0.4-mm voxels produced good measurement reliability and did not significantly differ from each other (P ≥ .20). CONCLUSIONS: CBCT scans with 0.2-mm and 0.4-mm voxel sizes delivered similarly accurate models. Larger voxels can be used to minimize radiation exposure.

Point-of-care, smartphone-based, dual-modality, dual-view, oral cancer screening device with neural network classification for low-resource communities.

Oral cancer is a growing health issue in a number of low- and middle-income countries (LMIC), particularly in South and Southeast Asia. The described dual-modality, dual-view, point-of-care oral cancer screening device, developed for high-risk populations in remote regions with limited infrastructure, implements autofluorescence imaging (AFI) and white light imaging (WLI) on a smartphone platform, enabling early detection of pre-cancerous and cancerous lesions in the oral cavity with the potential to reduce morbidity, mortality, and overall healthcare costs. Using a custom Android application, this device synchronizes external light-emitting diode (LED) illumination and image capture for AFI and WLI. Data is uploaded to a cloud server for diagnosis by a remote specialist through a web app, with the ability to transmit triage instructions back to the device and patient. Finally, with the on-site specialist's diagnosis as the gold-standard, the remote specialist and a convolutional neural network (CNN) were able to classify 170 image pairs into 'suspicious' and 'not suspicious' with sensitivities, specificities, positive predictive values, and negative predictive values ranging from 81.25% to 94.94%.

Automatic classification of dual-modalilty, smartphone-based oral dysplasia and malignancy images using deep learning.

With the goal to screen high-risk populations for oral cancer in low- and middle-income countries (LMICs), we have developed a low-cost, portable, easy to use smartphone-based intraoral dual-modality imaging platform. In this paper we present an image classification approach based on autofluorescence and white light images using deep learning methods. The information from the autofluorescence and white light image pair is extracted, calculated, and fused to feed the deep learning neural networks. We have investigated and compared the performance of different convolutional neural networks, transfer learning, and several regularization techniques for oral cancer classification. Our experimental results demonstrate the effectiveness of deep learning methods in classifying dual-modal images for oral cancer detection.

Paclitaxel and spirulina co-loaded polymeric nanoparticles: in-vitro and in-vivo anticancer study

Paclitaxel spirulina nanoparticles were said to have promising anticancer activity against gastric cancer. Nanoparticles of paclitaxel-spirulina were prepared for treating gastric cancer using precipitation technique. The synergistic anticancer efficiency againstMKN45 cells retains when the paclitaxel and spirulina were encapsulated into nanoparticles. To increase the site specific delivery, intra-tumoral administration was carried in the in vivo evaluation. There was an increase in overall survival in an MKN45-transplanted mice model and notable improvement in anti-tumour efficacy when paclitaxel-spirulina nanoparticles were delivered through intra-tumoral administration. The further investigation of overall anticancer mechanism of these nanoparticles is made as a major part in this research. Hence, the conjecture of this research is that, the paclitaxel-spirulina encapsulated nanoparticles could be an effective chemotherapeutic formulation for gastric cancer.

Mutualism-parasitism paradigm synthesized from results of root-endophyte models.

Plant tissues host a variety of fungi. One important group is the dark septate endophytes (DSEs) that colonize plant roots and form characteristic intracellular structures - melanized hyphae and microsclerotia. The DSE associations are common and frequently observed in various biomes and plant taxa. Reviews suggest that the proportion of plant species colonized by DSE equal that colonized by AM and microscopic studies show that the proportion of the root system colonized by fungi DSE can equal, or even exceed, the colonization by AM fungi. Despite the high frequency and suspected ecological importance, the effects of DSE colonization on plant growth and performance have remained unclear. Here, we draw from over a decade of experimentation with the obscure DSE symbiosis and synthesize across large bodies of published and unpublished data from Arabidopsis thaliana and Allium porrum model systems as well as from experiments that use native plants to better resolve the host responses to DSE colonization. The data indicate similar distribution of host responses in model and native plant studies, validating the use of model plants for tractable dissection of DSE symbioses. The available data also permit empirical testing of the environmental modulation of host responses to DSE colonization and refining the "mutualism-parasitism-continuum" paradigm for DSE symbioses. These data highlight the context dependency of the DSE symbioses: not only plant species but also ecotypes vary in their responses to populations of conspecific DSE fungi - environmental conditions further shift the host responses similar to those predicted based on the mutualism-parasitism-continuum paradigm. The model systems provide several established avenues of inquiry that permit more detailed molecular and functional dissection of fungal endophyte symbioses, identifying thus likely mechanisms that may underlie the observed host responses to endophyte colonization.

Arabidopsis thaliana model system reveals a continuum of responses to root endophyte colonization.

We surveyed the non-mycorrhizal model plant Arabidopsis thaliana microscopically for its ability to form dark septate endophyte (DSE) symbioses in field, greenhouse, and laboratory studies. The laboratory studies were also used to estimate host growth responses to 34 Periconia macrospinosa and four Microdochium sp. isolates. Consistent with broad host range observed in previous experiments, field-, greenhouse-, and laboratory-grown A. thaliana were colonized by melanized inter- and intracellular hyphae and microsclerotia or chlamydospores indicative of DSE symbiosis. Host responses to colonization were variable and depended on the host ecotype. On average, two A. thaliana accessions (Col-0 and Cvi-0) responded negatively, whereas one (Kin-1) was unresponsive, a conclusion consistent with our previous analyses with forbs native to the field site where the fungi originate. Despite the average negative responses, examples of positive responses were also observed, a conclusion also congruent with earlier studies. Our results suggest that A. thaliana has potential as a model for more detailed dissection of the DSE symbiosis. Furthermore, our data suggest that host responses are controlled by variability in the host and endophyte genotypes.

Oral adverse effects of gastrointestinal drugs and considerations for dental management in patients with gastrointestinal disorders.

Gastrointestinal disease is associated with alterations in the mouth or influence the course of the dental diseases, and the dental health care workers are expected to recognize, diagnose, and treat oral conditions associated with gastrointestinal diseases and also provide safe and appropriate dental care for afflicted individuals. Drugs used in the management of these diseases result in oral adverse effects and also are known to interact with those prescribed during dental care. Hence, this article has reviewed the drug considerations and guidelines for drug use during dental management of patients with gastrointestinal diseases.