Characterization of PEDOT:PSS Nanofilms Printed via Electrically Assisted Direct Ink Deposition with Ultrasonic Vibrations

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has emerged as a promising conductive polymer for constructing efficient hole-transport layers (HTLs) in perovskite solar cells (PSCs). However, conventional fabrication methods, such as spin coating, spray coating, and slot-die coating, have resulted in PEDOT:PSS nanofilms with limited performance, characterized by a low density and non-uniform nanostructures. We introduce a novel 3D-printing approach called electrically assisted direct ink deposition with ultrasonic vibrations (EF-DID-UV) to overcome these challenges. This innovative printing method combines programmable acoustic field modulation with electrohydrodynamic spraying, providing a powerful tool for controlling the PEDOT:PSS nanofilm's morphology precisely. The experimental findings indicate that when PEDOT:PSS nanofilms are crafted using horizontal ultrasonic vibrations, they demonstrate a uniform dispersion of PEDOT:PSS nanoparticles, setting them apart from instances involving vertical ultrasonic vibrations, both prior to and after the printing process. In particular, when horizontal ultrasonic vibrations are applied at a low amplitude (0.15 A) during printing, these nanofilms showcase exceptional wettability performance, with a contact angle of 16.24°, and impressive electrical conductivity of 2092 Ω/square. Given its ability to yield high-performance PEDOT:PSS nanofilms with precisely controlled nanostructures, this approach holds great promise for a wide range of nanotechnological applications, including the production of solar cells, wearable sensors, and actuators.

Ultrafast and Large-Scale Fabrication of PEDOT:PSS Nanofilms Using Electrical-Field-Assisted Direct Ink Deposition

The importance of conductive polymers has significantly increased over the decade due to their various applications, such as in electronic devices, sensors, and photovoltaics. Poly(3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT:PSS) is one of the most successfully and widely used polymers in practical applications. Spin coating is extensively used to fabricate these conductive films; however, it has disadvantages. It is inherently a batch process with relatively low output and high solution wastage. To address these issues, we developed a novel printing process called electrical-field-assisted direct ink deposition (EF-DID), which yields a continuous, homogenous film with high electrical conductivity. In this process, we studied the formation of nanodroplets under an electrical field and their effects on film characteristics. Furthermore, dimethyl sulfoxide (DMSO) was considered as an additive solvent to increase the conductivity and wettability of the films. We then compared EF-DID-printed PEDOT:PSS films with spin-coated films to better understand the film properties. Finally, inverted perovskite solar cell devices were fabricated and compared, where the PEDOT:PSS layers were prepared by EF-DID printing and spin coating. Based on the experimental results, a solution of 20% PEDOT:PSS in DMSO (vol/vol) printed by EF-DID for 15 s provided optimal morphology.

Assessment of gamma radiation through agro-morphological characters in Camellia Sinensis L. (O.) Kuntze

PURPOSE

To study the effects of gamma radiation on tea seed germination, morphological changes, and genetic variation by using gamma radiation.

MATERIAL AND METHOD

Fresh Tea seed material were irradiated with twenty different doses of gamma radiation such as 0, 2, 4, 6, 8, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80 90, 100, 200, 500 and 1000 Gy from Cobalt ⁶⁰Co source from Regional Nuclear Agriculture Research Center, Bidhan Chandra Krishi Viswavidyalaya (BCKV), West Bengal, in between 2019 and 2020.

RESULT AND CONCLUSION

The growth behavior of tea seedling was recorded under varying levels of gamma radiation and its performance at nursery stages. It was observed seed irradiated with doses from 35 Gy to 100 Gy could germinate but could not survive beyond five (05) months. When treated with higher doses as 200 Gy, 500 Gy and 1000 Gy, no seed germination takes places due to possible damages occur in the DNA structure. Screening of growth characteristics of tea plant generally monitored by the characteristics like plant height, number of leaves, number of primary branches, base diameter, and total leaf area of plants and we found that these characteristics significantly increased with the progress of time and increasing levels of gamma radiation; however, the plant height showed decreasing trend with the increasing levels of gamma radiation, which could be due to the change in chromosomal structure and genetic alteration. After 90 weeks of planting, the plant height, no. of primary branches, the number of leaves, plant base diameter, and total leaf area per plant recorded were 36.42 cm, 1/plant, 7.11/plant, 0.62 c.m, 22.92 cm²/plant respectively under the radiation level 30 Gy, whereas the corresponding figures of the above parameters at the control treatment were 85.32 cm, 1/plant, 18.84/plant, 1.18 c.m and 26.68 cm²/plant, respectively. The total plant height, no. of primary branches, the number of leaves, plant base diameter, and total leaf area per plant were significantly influenced by the rising levels of gamma radiation (up to 100 Gy), finally, after 90 weeks of planting, the maximum no. of branching was observed in the treatment of 8 Gy, 10 Gy and 15 Gy respectively. The study reveals a hitherto open the possibility of using gamma radiation on tea plant for creation of variation in the tea seed planting materials. Further studies on mutation using tea planting materials would give an insight into its mutable gene behavior.

Anteromedial Surface Plating for Midshaft Fracture Humerus Through an Anterolateral Approach - A Better Option than Anterolateral Plating

Introduction

Osteosynthesis by plate fixation of humeral shaft fractures as a gold standard for fracture fixation has been proven beyond doubt. However, during conventional anterolateral plating Radial nerve injury may occur which can be avoided by applying plate on the medial flat surface. The aim of this study was to evaluate the results of application of plate on the flat medial surface of humerus rather than the conventional anterolateral surface.

Materials and Methods

This study was conducted between Oct 2010 to Dec 2015. One-hundred-fifty fracture shafts of the humerus were treated with the anteromedial plating through the anterolateral approach.

Results

One-hundred-fifty patients with a fracture shaft of the humerus were treated with anteromedial plating. Twenty were female (mean ±SD,28 years±4.5) and 130 were male (mean ± SD, 38 years±5.6). One hundred and forty-eight out of 150 (98.6%) patients achieved union at 12 months. Two of three patients developed a superficial infection, both of which were treated successfully by antibiotics and one developed a deep infection, which was treated by wound debridement, prolonged antibiotics with the removal of the plate and subsequently by delayed plating and bone grafting.

Conclusion

In the present study, we applied plate on the anteromedial flat surface of humerus using the anterolateral approach. It is an easier and quicker fixation as compared to anterolateral plating because later involved much more dissection than a medial application of the plate and this application of plate on a medial flat surface, does not required Radial nerve exposure and palsy post-operatively. The significant improvement in elbow flexion without brachialis dissection is also a potential benefit of this approach. Based on our results, we recommend the application of an anteromedial plate for treatment of midshaft fractures humerus.

MR Geyser Sign in chronic rotator cuff tears

Acromio-clavicular (AC) joint cysts are rare presentation of chronic shoulder pathology. These cysts may be observed secondary to either degenerative changes in the AC joint with an intact rotator cuff (type 1 cyst) or following a chronic rotator cuff tear (type 2 cyst). The latter phenomenon is known as Geyser Sign and is described by ultrasound, conventional arthrogram and magnetic resonance imaging (MRI). We present a case of chronic rotator cuff tear presenting with a large type 2 cyst and Geyser Sign on MRI.

Development of an effective and efficient DNA isolation method for Cinnamomum species

Different species of Cinnamomum are rich in polysaccharide's and secondary metabolites, which hinder the process of DNA extraction. High quality DNA is the pre-requisite for any molecular biology study. In this paper we report a modified method for high quality and quantity of DNA extraction from both lyophilized and non-lyophilized leaf samples. Protocol reported differs from the CTAB procedure by addition of higher concentration of salt and activated charcoal to remove the polysaccharides and polyphenols. Wide utility of the modified protocol was proved by DNA extraction from different woody species and 4 Cinnamomum species. Therefore, this protocol has also been validated in different species of plants containing high levels of polyphenols and polysaccharides. The extracted DNA showed perfect amplification when subjected to RAPD, restriction digestion and amplification with DNA barcoding primers. The DNA extraction protocol is reproducible and can be applied for any plant molecular biology study.