Nonlinear optical properties of stilbene and azobenzene derivatives containing azaphosphane groups

We have studied the nonlinear optical (NLO) properties of some donor-acceptor molecules with stilbene and azobenzene molecules as backbone. We have used the nitro group as the acceptor and azaphosphane (R3P=N-) as the donor group. To study the effect of variation of NLO properties, we have replaced the substituents (Rs) connected to the phosphorus atom by methyl, amine and phenyl groups. We find that both first-order polarizability and hyperpolarizabilities are larger for stilbene derivatives and is maximum for the phenyl substitution. Second-order polarizability is higher for methyl substitution. We have also obtained the two-photon absorption cross-section for these molecules. We find that both one-photon and two-photon absorption cross-sections are maximum for the same excited state (first excited state in the case of stilbene and second excited state in the case of azobenzene derivatives)

Effect of Agrobacterium Infection Time, Co-Cultivation and Cell Density on in vitro Response in Hypocotyl of Eggplant (Solanum melongena L.)

The present study purports to assess the effect of Agrobacterium infection time, co-cultivation and cell density on in vitro response in hypocotyl explants of eggplant (brinjal) cv. Manjarigota. Agrobacterium(OD600 0.3-0.5) infection for 10-15 minutes (24.44±2.34%) was found to be optimum, while, higher or lower infection-time resulted in reduced callus initiation, shoot regeneration and explant survival. Explants with no (only Agrobacterium infection) or short (1 day) co-cultivation, showed reduced callus-initiation response and turned yellow, with no regeneration. Callus-initiation response increased from Day 1 (96.66±03.33%), and reached a maximum on Day 2 and Day 3 (100±00.00%). It decreased on further increase in co-cultivation time. Explants co-cultivated for three days showed highest regeneration response (30.00±02.96%) which thereafter reduced with further increase in co-cultivation time. Explants infected with Agrobacterium culture at 0.05 OD600 showed hardly any regeneration, and turned yellow and necrotic on the selection medium. Highest regeneration response (28.33±02.33%) was obtained in explants infected with 0.1 OD600 culture, and this gradually reduced as celldensity increased (upto 1.0 OD600), becoming zero in explants treated with cultures at 1.5 OD600 or above. Agrobacterium overgrowth was noticed on explants infected with cultures of 0.5 OD600 and above. Exposure of hypocotyl explants to higher cell-density, longer infection-time and prolonged co-cultivation regime resulted in severe necrosis of explants; time taken for development of Agrobacterium overgrowth was less with increase in the level of these factors. Regenerated shoots were healthy, green, elongated and showed root induction on culture medium containing Kanamycin

Factors Affecting in Vitro Shoot Regeneration in Hypocotyls of Brinjal (Solanum melongena L.) in the Early Steps of Agrobacterium-Mediated Transformation

An attempt was made to assess the effect of size, age and position of the explant, pre-culture and high cytokinin concentration in the pre-culture medium on shoot regeneration in brinjal hypocotyls co-cultivated with Agrobacterium. The study was carried out using hypocotyl explants of brinjal cv. Manjarigota, Agrobacterium strain A208 and shoot regeneration medium (full-strength basal MS medium, 2μM BAP + 0.05μM NAA, 3% sucrose and 0.8% agar) containing Cefotaxime (250-500mg l-1) and Kanamycin (100mg l-1). Hypocotyl explants showed callus initiation and shoot regeneration response after 10-12 and 20-22 days of culture, respectively. Five-day-old explants did not survive Agrobacterium infection, and ten-day-old explants showed higher shoot regeneration (29±1.91%) than older explants. Explants of medium size (1cm long; 32±2.62%) from the apical region (38.57±2.61%) showed better shootregeneration ability than explants of any other size or region. A period of four days of pre-culture (33.33±3.76) was optimal best for best shoot-regeneration in hypocotyl explants. No regeneration was seen in hypocotyl explants at shorter or longer pre-culture period. High cytokinin (10μM) in shoot regeneration medium during pre-culture enhanced shoot regeneration response (47.27±2.98%) in explants co-cultivated with Agrobacterium. Effects of various factors documented in this study will be useful in developing an efficient Agrobacterium-mediated transformation protocol in brinjal cv. Manjarigota

Submarine Escape Set Test Facilities

Submarine Escape Set (SES) is used by submariners to escape from a sunken submarine. This set caters for breathing needs of the submariner under water, until he reaches the surface. Evaluation of such life-saving equipment is of paramount importance. This paper describes the submarine escape set and various constructional features and schedules of operation of test facilities designed indegenously and which can evaluate the SES. The test facility is divided into two parts: the reducer test facility, and the breathing bag test facility. The equipment has been rigorously tested and accepted by Indian Navy. Two such test facilities have been developed, one of which is installed at INS Satavahana, Visakhapatnam, and are working satisfactorily

Effect of Age and Size of Hypocotyl Explant on in vitro Shoot Regeneration in Eggplant

In the present study, effect of size and age of hypocotyl explant on in vitro organogenetic responses was assessed in eggplant cv. Manjarigota. Size and age did not affect callus-initiation response, but showed marked influence on shoot regeneration response. Hypocotyl explants 1.5cm long showed highest shoot regeneration response (77.4%); either increase or decrease in size resulted in reduced response. Five to 15 day old hypocotyl explants showed direct shoot regeneration from cut ends, whereas 20-30 day old hypocotyl explants showed indirect shoot regeneration from callus produced on cut ends. Five day old explants were most responsive, with highest (91.23%) and thirty day old explants least responsive with reference to shoot regeneration response (20.85%). Shoot regeneration frequency decreased with increasing age, whereas shoot regeneration efficiency increased with increasing age of hypocotyl explants

Cellular Senescence in Aging Lungs and Diseases

Cellular senescence represents a state of irreversible cell cycle arrest occurring naturally or in response to exogenous stressors. Following the initial arrest, progressive phenotypic changes define conditions of cellular senescence. Understanding molecular mechanisms that drive senescence can help to recognize the importance of such pathways in lung health and disease. There is increasing interest in the role of cellular senescence in conditions such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) in the context of understanding pathophysiology and identification of novel therapies. Herein, we discuss the current knowledge of molecular mechanisms and mitochondrial dysfunction regulating different aspects of cellular senescence-related to chronic lung diseases to develop rational strategies for modulating the senescent cell phenotype in the lung for therapeutic benefit

Community detection of the framing element network: proposing and assessing a new computational framing analysis approach

The evolving computational news framing detection has been a prominent yet contested field among mass communication scholars. This study explores a new approach to identifying frames as clusters of framing elements including actors (i.e., individual and organizational entities) and topics in news articles based on the community detection algorithm. Our approach highlights the fundamental importance of considering individual and organizational actors mentioned in news articles as components of frames, which is overlooked in previous research that uses a similar unsupervised approach. We evaluate the performance of our method by comparing it with one of the most popular unsupervised methods--LDA topic modeling--and a state-of-art deep learning method, BERT, based on 2,900 US gun violence news articles.Abstrac

Effect of Antibiotics and Gelling Agents in Transformation of Brinjal (Solanum melongena L.) cv. Manjarigota

A study was conducted to find out the effect of antibiotics and gelling agents on Agrobacterium-mediated transformation using hypocotyl explants of brinjal cv. Manjarigota. Hypocotyl explants of brinjal were found to be sensitive even to the lowest level of kanamycin (25 mg/l) tested. Explants that showed increased callus initiation and regeneration response upon cocultivation with Agrobacterium and on kanamycin at 100 mg/l were selected as this indicated a highly effective selection pressure. Cefotaxime did not affect regeneration response and at 500 mg/l, it effectively inhibited Agrobacterium overgrowth completely on Agrobacterium cocultivated hypocotyl explants. There were marked differences in regeneration response in hypocotyl explants cultured on medium solidified with various gelling agents indicating the influence of gelling agent on the activity of kanamycin in culture medium, which indirectly affects selection and recovery of transformants. Antibiotics and gelling agents could therefore affect, directly or indirectly, transformation of brinjal cv. Manjarigota

Effects of Growth Regulators and Explant-Type on Agrobacterium-Mediated Transformation in Brinjal (Solanum melongena L.) cv. Manjarigota

Effects of growth regulators and type of explants on transformation and in vitro morphogenetic responses of brinjal cv. Manjarigota were studied. Both hypocotyl and cotyledonary explants showed marked influence on in vitro morphogenetic responses after Agrobacterium co-cultivation. Hypocotyl explants showed callus initiation and regeneration responses earlier than cotyledonary leaves. Hypocotyl explants were found to be better than cotyledonary leaf explants in regenerating shoots after Agrobacterium co-cultivation. There was delay and reduction in both callus and regeneration responses in Agrobacterium co-cultivated explants. Hypocotyl explants showed the highest regeneration response on MS medium containing 2 μM BAP and 0.05 μM NAA while cotyledonary leaves did not show regeneration response after Agrobacterium co-cultivation. However, they showed green buds on MS medium containing 10 μM BAP and 1 μM NAA, which could not differentiate into shoots. Overall, hypocotyl explants were found better in regenerating shoots after Agrobacterium co-cultivation