End-capped engineering of Quinoxaline core-based non-fullerene acceptor materials with improved power conversion efficiency

Improving the light-harvesting efficiency and boosting open circuit voltage are crucial challenges for enhancing the efficiency of organic solar cells. This work introduces seven new molecules (SA1-SA7) to upgrade the optoelectronic and photovoltaic properties of Q-C-F molecule-based solar cells. All recently designed molecules have the same alkyl-substituted Quinoxaline core and CPDT donor but vary in the end-capped acceptor subunits. All the investigated molecules have revealed superior properties than the model (R) by having absorbance ranging from 681 nm to 782 nm in the gaseous medium while 726 nm-861 nm in chloroform solvent, with the lowest band gap ranging from 1.91 to 2.19 eV SA1 molecule demonstrated the highest λmax (861 nm) in chloroform solvent and the lowest band gap (1.91 eV). SA2 molecule has manifested highest dipole moment (4.5089 D), lower exciton binding energy in gaseous (0.33 eV) and chloroform solvent (0.47 eV), and lower charge mobility of hole (0.0077693) and electron (0.0042470). At the same time, SA7 showed the highest open circuit voltage (1.56 eV) and fill factor (0.9166) due to solid electron-pulling acceptor moieties. From these supportive outcomes, it is inferred that our computationally investigated molecules may be promising candidates to be used in advanced versions of OSCs in the upcoming period.

Enhancing systematic tolerance in Bermuda grass (Cynodon dactylon L.) through amplified alkB gene expression and bacterial-driven hydrocarbon degradation

This study aimed to access the impact of soil polluted with petroleum (5, 10 g petroleum kg-1 soil) on Bermuda grass (Cynodon dactylon L.) with and without applied bacterial inoculants (Arthrobacter oxydans ITRH49 and Pseudomonas sp. MixRI75). Both soil and seed were given bacterial inoculation. The evaluated morphological parameters of Bermuda grass were fresh and dry weight. The results demonstrated that applied bacterial inoculants enhanced 5.4%, 20%, 28% and 6.4%, 21%, and 29% shoot and root fresh/dry weights in Bermuda grass under controlled environment. The biochemical analysis of shoot and root was affected deleteriously by the 10 g petroleum kg-1 soil pollution. Microbial inoculants enhanced the activities of enzymatic (catalase, peroxidase, glutathione reductase, ascorbate peroxidase, superoxide dismutase) and non-enzymatic (ɑ-tocopherols, proline, reduced glutathione, ascorbic acid) antioxidant to mitigate the toxic effects of ROS (H2O2) under hydrocarbon stressed condition. The maximum hydrocarbon degradation (75%) was recorded by Bermuda grass at 5 g petroleum kg-1 soil contamination. Moreover, bacterial persistence and alkane hydroxylase gene (alkB) abundance and expression were observed more in the root interior than in the rhizosphere and shoot interior of Bermuda grass. Subsequently, the microbe used a biological tool to propose that the application of plant growth-promoting bacteria would be the most favorable choice in petroleum hydrocarbon polluted soil to conquer the abiotic stress in plants and the effective removal of polyaromatic hydrocarbons in polluted soil.

Silicon-Induced Mitigation of NaCl Stress in Barley (Hordeum vulgare L.), Associated with Enhanced Enzymatic and Non-Enzymatic Antioxidant Activities

Salt stress obstructs plant's growth by affecting metabolic processes, ion homeostasis and over-production of reactive oxygen species. In this regard silicon (Si) has been known to augment a plant's antioxidant defense system to combat adverse effects of salinity stress. In order to quantify the Si-mediated salinity tolerance, we studied the role of Si (200 ppm) applied through rooting media on antioxidant battery system of barley genotypes; B-10008 (salt-tolerant) and B-14011 (salt-sensitive) subjected to salt stress (200 mM NaCl). A significant decline in the accumulation of shoot (35-74%) and root (30-85%) biomass was observed under salinity stress, while Si application through rooting media enhancing biomass accumulation of shoots (33-49%) and root (32-37%) under salinity stress. The over-accumulation reactive oxygen species i.e., hydrogen peroxide (H2O2) is an inevitable process resulting into lipid peroxidation, which was evident by enhanced malondialdehyde levels (13-67%) under salinity stress. These events activated a defense system, which was marked by higher levels of total soluble proteins and uplifted activities of antioxidants enzymatic (SOD, POD, CAT, GR and APX) and non-enzymatic (α-tocopherol, total phenolics, AsA, total glutathione, GSH, GSSG and proline) in roots and leaves under salinity stress. The Si application through rooting media further strengthened the salt stressed barley plant's defense system by up-regulating the activities of enzymatic and non-enzymatic antioxidant in order to mitigate excessive H2O2 efficiently. The results revealed that although salt-tolerant genotype (B-10008) was best adopted to tolerate salt stress, comparably the response of salt-sensitive genotype (B-14011) was more prominent (accumulation of antioxidant) after application of Si through rooting media under salinity stress.

Induced systemic tolerance mediated by plant-microbe interaction in maize (Zea mays L.) plants under hydrocarbon contamination

The present investigation was committed to examining the effect of soil spiked with diesel contamination (0, 1.5, 2.5, 3.5 g diesel kg^-1 soil) on maize (Zea mays L) varieties (MMRI yellow and Pearl white) with or without bacterial consortium (Pseudomonas aeruginosa BRRI54, Acinetobacter sp. strain BRSI56, Acinetobacter sp. strain ACRH80). Seed and soil bacterial inoculation were done. The studied morphological attributes were fresh and dry weight of shoot and root of both maize varieties. The results documented that bacterial consortium caused 21%, 0.06% and 29%, 34% higher shoot and root fresh/dry weights in "Pearl white" and 14%, 15% and 32%, 22% shoot and root fresh/dry weights respectively in MMRI yellow under control conditions. The biochemical attributes of shoot and root were affected negatively by the 3.5 g diesel kg^-1 soil contamination. Bacterial consortium enhanced enzymatic activity (APX, CAT, POD, SOD, GR) and non-enzymatic (AsA, GSH, Pro, α-Toco) antioxidant and reduction in oxidative stress (H₂O₂, MDA) under hydrocarbon stress as compared to non-inoculated ones in both root and shoot organs. Among both varieties, the highest hydrocarbon removal (75, 64, and 69%) was demonstrated by MMRI yellow with bacterial consortium as compare to Pearl white showed 73, 57, 65% hydrocarbon degradation at 1.5 2.5, 3.5 g diesel kg^-1 soil contamination. Consequently, the microbe mediated biotransformation of hydrocarbons suggested that the use of PGPB would be the most beneficial selection in diesel fuel contaminated soil to overcome the abiotic stress in plants and successfully remediation of hydrocarbon in contaminated soil.

Elucidating the distinct interactive impact of cadmium and nickel on growth, photosynthesis, metal-homeostasis, and yield responses of mung bean (Vigna radiata L.) varieties

Contamination of soils with heavy metals (HMs) caused serious problems because plants tend to absorb HMs from the soil. In view of HM hazards to plants as well as agro-ecosystems, we executed this study to assess metal toxicity to mung bean (Vigna radiata) plants cultivated in soil with six treatment levels of cadmium (Cd) and nickel (Ni) and to find metal tolerant variety, i.e., M-93 (V₁) and M-1(V₂) with multifarious plant biochemical and physiological attributes. Increasing doses of Cd and Ni inhibited plant growth and photosynthesis and both varieties showed highly significant differences in the morpho-physiological attributes. V₂ showed sensitivity to Cd and Ni treatments alone or in combination. Tolerance indices for attributes presented a declined growth of Vigna plants under HM stress accompanied by highly significant suppression in gas exchange characteristics. Of single element applications, the adverse effects on mung bean were more pronounced in Cd treatments. V₁ showed much reduction in photosynthesis attributes except sub-stomatal CO₂ concentration in all treatments compared to V₂. The yield attributes, i.e., seed yield/plant and 100-seed weight, were progressively reduced in T₅ for both varieties. In combination, we have observed increased mobility of Cd and Ni in both varieties. The results showed that water use efficiency (WUE) generally increased in all the treatments for both varieties compared to control. V₂ exhibited less soluble sugars and free amino acids compared to V₁ in all the treatments. Similarly, we recorded an enhanced total free amino acid contents in both varieties among all the metal treatments against control plants. We conclude that combinatorial treatment proved much lethal for Vigna plants, but V₁ performed better than V₂ in counteracting the adverse effects of Cd and Ni.

Foliar fertigation of ascorbic acid and zinc improves growth, antioxidant enzyme activity and harvest index in barley (Hordeum vulgare L.) grown under salt stress

Crop productivity is limited by several environmental constraints. Among these, salt stress plays a key role in limiting the growth and yield production of economically important agricultural crops. However, the exogenous fertigation of vitamins and minerals could serve as a "shot-gun" approach for offsetting the deleterious effects of salts present in the rhizosphere. Therefore, an experiment was conducted to quantify the efficacy of foliar fertigation of ascorbic acid (vitamin-C) and zinc (Zn) on the physio-biochemical attributes of barley (Hordeum vulgare L. Genotype B-14011) grown in a saline environment. The salt stress resulted in a reduced biological yield associated with a decrease in chlorophyll pigment, while a significant enhancement in Na⁺ and Zn²⁺ was observed under salinity stress. Similarly, the contents of total soluble proteins, total free amino acids, lipid peroxidation, and H₂O₂ and the activities of antioxidative enzymes (SOD, POD, CAT, APX and proline) were significantly enhanced under salinity stress. Moreover, salinity negatively affected the yield attributes and ion uptake of plants. However, foliar fertigation with AsA +0.03% Zn enhanced vegetative growth, photosynthetic pigments, synchronized ion uptake, the synthesis of enzymatic and non-enzymatic antioxidants, and the harvest index. It is inferred from this study that among all treatments, the effect of foliar fertigation with the AsA+0.03% Zn combination not only improved the salt stress tolerance but also improved the yield attributes, which will aid in the improvement in barley seed yield and is a step to solve the problem of malnutrition through biofortification of vitamin-C and zinc.

Seed morphology: An addition to the taxonomy of Astragaleae and Trifolieae (Leguminosae: Papilionoidae) from Pakistan

Seed morphology was described in detail for 12 species belonging to 5 genera of tribes Astragaleae and Trifolieae (Leguminosae; Papilionoideae) using scanning electron microscopy (SEM) to evaluate the taxonomic relevance of macromorphological and micromorphological seed characters. The study aims to search for diagnostic seed ultrastructural features that may help to elucidate species identification. For SEM analysis, seed morphological characters including seed form and shape, color and size, ornamentation, epidermal cell shape, and anticlinal wall pattern were investigated. As a result of the study, species-specific characters have been determined. Based on seed exomorphology, three characteristic cell patterns; irregular, round, and flat were observed. In majority of studied taxa, species may be further differentiated based on seed shape, size, and surface ornamentation. The inconsistency in testa cell pattern, shape, and distribution of papillae or protuberances may probably give further insight and significant morphological features at specific and generic level within the tribe. This study illustrated that considerable taxonomic knowledge can be obtained by examining the seed characters of Astragaleae and Trifolieae, particularly at the species level. The results demonstrated that the use of SEM in seed morphology could play a role in the identification of taxa particularly at genus and species level. Twelve species of Astragaleae and Trifolieae were studied in order to describe and investigate the seed morphology and to evaluate the diagnostic value of this character using a SEM. A broader taxon sampling is required for classification at generic and tribal level, besides molecular and phylogenetic studies.

First Report of Groundnut bud necrosis virus in Tomato in Bangladesh

An unusual disease of tomato characterized by leaf mottling and necrotic streaks on veins, shortened internodes, necrosis of terminal buds, and concentric rings on fruits was observed during 2010 to 2011 surveys in tomato growing regions of Godagari Upzila, Rajshahi district, Bangladesh. Disease incidence in popularly grown F1 hybrid cultivars, which include Sobal, Abhiruchi, Salamat, Bangobir, and BARI hybrid tomato-5 and -6 in about 40 commercial fields, ranged from 40 to 90%. Extracts from the field samples (n = 10) reacted with polyclonal antiserum to Groundnut bud necrosis virus (GBNV) in direct antigen coated ELISA, suggesting the association of a tospovirus antigenically related to serogroup IV topsovirus (1). To identify whether the tospovirus was a distinct virus species, ELISA-positive samples were subjected to total RNA extraction with an RNeasy Plant Mini Kit (Qiagen, Chatsworth, CA) followed by reverse transcription (RT)-PCR with tospovirus-specific primers (5'-ATGGTTGAAAAGAGCAAGAATGATGC-3') and degenerate primer (5'-CTTCTTATGAAGTGTACTCACCATAAGTCATCC-3') derived from the conserved sequences of GBNV, Watermelon bud necrosis virus (WBNV), and Capsicum chlorosis virus (CaCV) (2). The RT-PCR product was cloned into pGEM-T Easy vector (Promega, Madison, WI) and sequenced at Department of Biochemistry, University of Delhi, South Campus, Delhi, India (GenBank Accession No. JQ692083). The sequences of cloned fragments were assembled. Analysis of the 477-bp region of the nucleocapsid protein (N) gene revealed that the tomato tospovirus shared maximum identity both at the nucleotide (96%) and amino acid (97%) levels with the corresponding region of GBNV. In contrast, only 78 to 81% and 85 to 87% identity at nucleotide and amino acid levels, respectively, was observed with the corresponding region of the N genes of CaCV, WBNV, and Watermelon silver mottle virus. These results suggested the association of GBNV with the diseased tomato samples. To our knowledge, this is the first report of GBNV infecting tomato in Bangladesh and regular surveys are necessary to ascertain the prevalence and incidence of GBNV in other crops. References: (1) R. K. Jain et al. J. Virol. Methods 130:162, 2005. (2) M. Tsompana and J. W. Moyer. Tospovirus. Page 157 in: Encyclopedia of Virology. Academic Press, New York, 2009.

Epilepsy in children with cerebral palsy

This was a prospective analytical study done from October'99 through December 2000 to observe the clinical profile of epilepsy in children with cerebral palsy. Sixty epileptic children with cerebral palsy were studied and their results were compared with the results of epilepsy in 30 developmentally normal children. Ages of all children studied were 1-15 years. Majority were below five years of age and male out numbered female. Spastic quadriplegia (60%) was the commonest type of cerebral palsy. Generalized tonic-clonic seizure (66%) was the commonest seizure type in both groups. Second most common type of seizure was partial (13%) and myoclonic (29%) in developmentally normal and cerebral palsy children respectively. Mental retardation (63%) and speech delay (58%) were the two common associated problems in cerebral palsy patients. Ventriculomegaly (55%) was the commonest computed tomographic findings in cerebral palsy patients. In electro encephalography generalized epileptiform activity was the commonest finding in both groups. Clinical pattern is different in many ways when epilepsy is associated with cerebral palsy.

Effect of cimetidine, ranitidine and tiotidine on plasma testosterone and luteinizing hormone levels in rats

This investigation was carried out to study the comparative effects of cimetidine, ranitidine and tiotidine on the plasma levels of testosterone and luetinizing hormone under local conditions. The three H(2)-blocking drugs were injected to the adult male albino rats twice daily at the recommended therapeutic dose levels for six weeks. The data obtained showed that only tiotidine caused a significant (<0.05) increase in the level of testosterone. However, all the three drugs caused a significant rise in the levels of luteinizing hormone with the most active ranitidine administration.

Fetal exsanguination associated with antepartum hemorrhage

Fetal bleeding in utero is infrequent. It is usually life-threatening but can be treated successfully in most cases if recognized early. Four cases are described and it is suggested that screening for fetal blood be done in all instances of antepartum hemorrhage.

Respiratory distress syndrome and the value of amniotic fluid phospholipids in predicting such complications before birth

The amniotic fluid study of 80 samples from 40 patients, obtained by amniocentesis between 28 and 40 weeks of pregnancy, was carried out. It was noted that L/S (Lecithin/Sphingomyelin) ratio was significantly different at 36-38 weeks of pregnancy when compared with values in pregnancies of less than 36 weeks gestation (P less than 0001). No cases of RDS occurred when the L/S ratio was mature 4 or more. A brief review of recent developments in etiology of RDS are also presented.

The use of ultrasound in obstetrics and gynecology

Advantages of ultrasound as a diagnostic tool are many. The patient experiences no discomfort, nor does she feel any sensation. The patient can be examined without moving from her bed. Unlike x-ray, there is no danger of exposing the fetus and the mother to adverse effects of radiation. Its application in determination of fetal death, early in pregnancy, diagnosis of hydatidiform mole and localization of the placenta in cases of antepartum hemorrhage are only some of the obvious applications of this method.