Cellulose Nanocrystal-Based All-3D-Printed Pyro-Piezoelectric Nanogenerator for Hybrid Energy Harvesting and Self-Powered Cardiorespiratory Monitoring toward the Human-Machine Interface.

Biomaterials with spontaneous piezoelectric property are highly emerging in recent times for the generation of electricity from mechanical energy sources that are amply available in nature. In this context, pyroelectricity, an integral property of piezoelectric materials, might be an interesting tool in harvesting thermal energy from the fluctuations of temperature. On the other hand, respiration and heart pulse are the significant human vital signs that can be used for early detection and prevention of cardiorespiratory diseases. Here, we report an all-three-dimensional (3D)-printed pyro-piezoelectric nanogenerator (Py-PNG) based on the most abundant and completely biodegradable biopolymer on earth, i.e., cellulose nanocrystal (CNC) for hybrid (mechanical as well as thermal) energy harvesting, and interestingly, the NG could be used as an e-skin sensor for application in self-powered noninvasive cardiorespiratory monitoring for personal healthcare. Notably, the CNC-based device will be biocompatible and economically advantageous due to its biomaterial-based supremacy and huge availability. This is an original approach with 3D geometrical advancement in designing a NG/sensor, where the unique all-3D-printed manner is adopted, and certainly, it has promising potential in reducing the number of processing steps to required equipment during the multilayer fabrication. The all-3D-printed NG/sensor shows outstanding mechano-thermal energy harvesting performance along with sensitivity and is capable of accurate detection of heart pulse as well as respiration, whenever and whichever required without the need of any battery or an external power supply. In addition, we have also extended its application in demonstrating a smart mask-based breath monitoring system. Thus, the real-time cardiorespiratory monitoring provides notable and fascinating information in medical diagnosis, stepping toward biomedical device development and human-machine interface.

Natural Sugar-Assisted, Chemically Reinforced, Highly Durable Piezoorganic Nanogenerator with Superior Power Density for Self-Powered Wearable Electronics.

Natural piezoelectric materials are of increasing interest, particularly for applications in biocompatible, implantable, and flexible electronic devices. In this paper, we introduce a cost-effective, easily available natural piezoelectric material, that is, sugar in the field of wearable piezoelectric nanogenerators (PNGs) where low electrical output, biocompatibility, and performance durability are still critical issues. We report on a high-performance piezoorganic nanogenerator (PONG) based on the hybridization of sugar-encapsulated polyvinylidene fluoride (PVDF) nanofiber webs (SGNFW). We explore the crucial role of single-crystal sugar having a fascinating structure along with the synergistic enhancement of piezoelectricity during nanoconfinement of sugar-interfaced macromolecular PVDF chains. As a consequence, the SGNFW-based PONG exhibits outstanding electricity generation capability (e.g., ∼100 V under 10 kPa human finger impact and maximum power density of 33 mW/m2) in combination with sensitivity to abundantly available different mechanical sources (such as wind flow, vibration, personal electronics, and acoustic vibration). Consequently, it opens up suitability in multifunctional self-powered wearable sensor designs for realistic implementation. In addition, commercially available capacitors are charged up effectively by the PONG because of its rapid energy storage capability. The high performance of the PONG not only offers "battery-free" energy generation (several portable units of light-emitting diodes and a liquid crystal display screen are powered up without using external storage) but also promises its use in wireless signal transmitting systems, which widens the potential in personal health care monitoring. Furthermore, owing to the geometrical stress confinement effect, the PONG is proven to be a highly durable power-generating device validated by stability test over 10 weeks. Therefore, the organic nanogenerator would be a convenient solution for portable personal electronic devices that are expected to operate in a self-powered manner.

All-Organic High-Performance Piezoelectric Nanogenerator with Multilayer Assembled Electrospun Nanofiber Mats for Self-Powered Multifunctional Sensors.

Rapid development of wearable electronics, piezoelectric nanogenerator (PNG), has been paid a special attention because of its sustainable and accessible energy generation. In this context, we present a simple yet highly efficient design strategy to enhance the output performance of an all-organic PNG (OPNG) based on multilayer assembled electrospun poly(vinylidene fluoride) (PVDF) nanofiber (NF) mats where vapor-phase polymerized poly(3,4-ethylenedioxythiophene)-coated PVDF NFs are assembled as electrodes and neat PVDF NFs are utilized as an active component. In addition to the multilayer assembly, electrode compatibility and durability remain a challenging task to mitigate the primary requirements of wearable electronics. A multilayer networked three-dimensional structure integrated with a compatible electrode thereby provides enhanced output voltage and current (e.g., open-circuit voltage, Voc ≈ 48 V, and short-circuit current, Isc ≈ 6 µA, upon 8.3 kPa of the applied stress amplitude) with superior piezoelectric energy conversion efficiency of 66% compared to the single-mat device. Besides, OPNG also shows ultrasensitivity toward human movements such as foot strikes and walking. The weight measurement mapping is critically explored by principal component analysis that may have enormous applications in medical diagnosis to smart packaging industries. More importantly, fatigue test under continuous mechanical impact (over 6 months) shows great promise as a robust wearable mechanical energy harvester.

Rhinosporidiosis of lacrimal sac: An interesting case of orbital swelling.

Rhinosporidiosis is a chronic localized granulomatous disease caused by Rhinosporidium seeberi, an aquatic protistan parasite belonging to a clade, Mesomycetozoea. Infestation of Rhinosporidiosis to the eye and adnexa is termed oculosporidiosis, in such cases, conjunctival mucosa is mostly involved; however in our case, it involved only the lacrimal sac and deeper periorbital tissue and presented as a case of orbital swelling. Surgical excision of the lesion was done, postoperatively dapsone therapy was given for 6 months, and the patient responded very well with no recurrence till date.

A study on outcome of underlay, overlay and combined techniques of myringoplasty.

Myringoplasty is a procedure which deals on repair of the tympanic membrane. This procedure can be done via postaural, endaural or endomeatal route. Various grafts such as temporalis fascia, vein graft, perichondrium are used. The technique can be categorized as underlay, overlay, interlay or its combination depending on the placement of the graft material. This study was done to compare underlay, overlay and combined technique in terms of the closure of the membrane defect, postoperative complications and over all success rates. Apart from few complications, this study revealed over all success rate was best with combined technique but the difference was not significant statistically when the methods are comparable among them.

Clinico-epidemiological profile of chronic suppurative otitis media patients attending a tertiary care hospital.

The cross-sectional study was conducted to assess the clinico-epidemiological profile, perceptions and clinical profile of the chronic suppurative otitis media (CSOM) patients in a tertiary care hospital. A pretested questionnaire was used containing open questions and the patients were assessed clinically. Most patients (31.2%) were from 0-10 years age group and were males (58.8%). Majority of them (96%) lived in "kuccha" houses/slums, 76.8% practised unhygienic ear pricking, 36.8% poured oil in their ears, 70.8% bathed in ponds/rivers, 52.8% had ear discharge for more than 1 year. Among the respondents, 17.2% knew that CSOM was contagious, 24% thought CSOM ran in family, 20% knew CSOM is preventable. There was low threat perception and long time to seek care. Patients mostly presented with earache, deafness and discharge, most had deafness and safe variety of CSOM. More than half had comorbidities. Most of the previous study findings corroborated with the present study. Here was a substantial delay between the onset and treatment seeking due to lack of awareness and low threat perception. Pain and complications were the triggers for care-seeking. Education about the disease, strengthening the frontline workers and good referral system are suggested.

A study on role of nasal endoscopy for diagnosis and management of epistaxis.

Epistaxis is one of the commonest ENT emergencies. It affects people of all ages, more commonly males. Bleeding may be due to local nasal pathology, systemic diseases, or sometimes no specific cause is found, which is called idiopathic epistaxis. This descriptive study was designed to evaluate role of nasal endoscopy for diagnosis and management of epistaxis in a tertiary care hospital. Sixty-two selected patients with active epistaxis or with history of epistaxis within last 24 hours were evaluated and underwent nasal endoscopy. Patients were managed following standard protocols. This study demonstrated a bimodal distribution with incidence peaks in below 20 years and above 50 years age groups. Males were affected nearly twice commonly as females. Anterior nasal bleeding was noted in majority. Most common cause was found to be hypertension closely followedby trauma. Nasal endoscopy helped to localise bleeding points in majority of the cases. Cases were managed accurately with the help of endoscopes and any local disease was eradicated thoroughly. During follow-up, endoscopy helped in early detection of recurrences and thereby prevented complications. Epistaxis can be controlled very efficiently by electro or chemical cauterisation with the help of endoscopes, the source can be localised more efficiently. In cases of failure to localise or access of bleeding points, anterior and/or posterior nasal packing can control majority of nosebleeds. In majority of cases non-surgical interventions were sufficient.