1,890 research outputs found
From Wires to Cables: Attempted Synthesis of 1,3,5-Trifluorenylcyclohexane as a Platform for Molecular Cables
Multiple molecular wires braided together in a single assembly, termed as molecular cable, are promising next-generation materials for effective long-range charge transport. As an example of the platform for constructing molecular cables, 1,3,5-trifluorenylcyclohexane (TFC) and its difluorenyl analogues (DFCs) were systematically investigated both experimentally (X-ray crystallography) and theoretically (DFT calculations). Although the syntheses of DFCs were successfully achieved, the synthesis of TFC, which involved a similar intramolecular Friedel–Crafts cyclization as the last step, was unsuccessful. An exhaustive study of the conformational landscape of cyclohexane ring of TFC and DFCs revealed that TFC is a moderately strained molecule (∼17 kcal/mol), and computational studies of the reaction profile show that this steric strain, present in the transition state, is responsible for the unusually high (∼5 years) reaction half-life. A successful synthesis of TFC will require that the steric strain is introduced in multiple steps, and such alternative strategies are being currently explored
A Study on the Cytological Effects of Myrobalan (Fruit of \u3cem\u3eTerminalia chebula\u3c/em\u3e) in \u3cem\u3eAllium\u3c/em\u3e Tests
The present study was aimed to find the cytogenetic effects of myrobalan using Allium cepa as a model system. The onion bulbs were grown in the suspension of myrobalan in tap water at various concentrations (0.01, 0.10, 1.0, 10.0 and 30 mg/ml) for 96 hours. The mean root length, the colour of growing roots as well as the mitotic index and chromosomal aberrations were observed in the presence of myrolaban, in order to assess the cytological effects of myrobalan. The colour of growing roots was not affected at 0.01 and 0.1 mg/ml myrobalan concentrations, while it appeared pale at 1 mg and 10 mg/ml and black at 30 mg/ml concentrations. The root length was not affected at low concentrations of myrobalan, however, concentrations 1 mg/ml and above inhibited root length. The mitotic index, i.e., percentage of dividing root tip cells did not change at 0.01 and 0.10 mg/ml myrobalan concentration, however, it decreased significantly at 1 mg/ml and no mitosis was observed at 10 mg/ml and above, as the cells were seen in interphase with nucleoli. Abnormal mitosis and chromosomal aberrations like sticky chromosomes, C–mitosis, laggards, multipolar anaphases, chromosome bridge, micronucleated cells and polykaryocytes were not seen in dividing and non-dividing cells among roots grown at various concentrations of myrobalan. The present finding reveals that myrobalan does not exert any cytotoxic effects in Allium model
Prevention of Aluminium Chloride-Induced Mitodepression with Myrobalan (Fruit of \u3cem\u3eTerminalia chebula\u3c/em\u3e, Retz, Combretaceae) in \u3cem\u3eAllium cepa\u3c/em\u3e Model
Allium cepa bulbs were grown in pure tap water (Group I), in five concentrations (10-1M to 10-5M) of aluminium chloride in the absence (Group II) and in the presence (Group III) of myrobalan (fruit of Terminalia chebula) at a fix concentration of 0.10 mg/ml. Parameters of study were mean root length (after 72 hr) and mitotic index, abnormal mistosis, chromosomal aberrations and nucleolar morphology (after 48 hr). AlCl3 at all concentrations except at 10-1M where roots did not grew at all, significantly lowered root growth and mitotic index, effect appeared concentration dependent (Group II). In the presence of myrobalan (Group III) AlCl3 induced mitodepression could be checked significantly only at 10-4M and 10-5M. No morphological i.e. shape and colour changes, abnormal mitosis and any type of chromosomal aberrations could be detected in any group. AlCl3 induced hypertrophy of nucleoli at 10-2M-10-5M which could be remedied at 10-4M and 10-5M in (Group III). Probable toxic action of AlCl3 and possible protective role of myrobalan are discussed
Charge Delocalization in Self-Assembled Mixed-Valence Aromatic Cation Radicals
The spontaneous assembly of aromatic cation radicals (D+•) with their neutral counterpart (D) affords dimer cation radicals (D2+•). The intermolecular dimeric cation radicals are readily characterized by the appearance of an intervalence charge-resonance transition in the NIR region of their electronic spectra and by ESR spectroscopy. The X-ray crystal structure analysis and DFT calculations of a representative dimer cation radical (i.e., the octamethylbiphenylene dimer cation radical) have established that a hole (or single positive charge) is completely delocalized over both aromatic moieties. The energetics and the geometrical considerations for the formation of dimer cation radicals is deliberated with the aid of a series of cyclophane-like bichromophoric donors with drastically varied interplanar angles between the cofacially arranged aryl moieties. X-ray crystallography of a number of mixed-valence cation radicals derived from monochromophoric benzenoid donors established that they generally assemble in 1D stacks in the solid state. However, the use of polychromophoric intervalence cation radicals, where a single charge is effectively delocalized among all of the chromophores, can lead to higher-order assemblies with potential applications in long-range charge transport. As a proof of concept, we show that a single charge in the cation radical of a triptycene derivative is evenly distributed on all three benzenoid rings and this triptycene cation radical forms a 2D electronically coupled assembly, as established by X-ray crystallography
Will Herbal-Paracetamol \u3cem\u3eCombination\u3c/em\u3e Drug Prevent both Liver and Kidney Disease? - Results and Possibilities
An attempt has been made to briefly review the existing information on herbal compounds which could combat acetaminophen (paracetamol) toxicity. A careful perusal of literature revealed that acetaminophen overdose not only damages liver but also the kidney. Nevertheless, the kidney was badly ignored in studies aimed at preventing paracetamol toxicity with herbal drugs. On account of such major neglect, so far no herbal-paracetamol combination could be made. Milk thistly is only well researched drug which appears as a suitable future candidate, but its action towards the kidney must be studied. The importance of such studies in the future is discussed
The Ayurveda Education in India: How Well Are the Graduates Exposed to Basic Clinical Skills?
“Ayurveda” is an ancient system of healthcare that is native to India. At present, in India, there are more than 240 colleges that offer a graduate-level degree (Bachelor of Ayurvedic Medicine and Surgery—BAMS) in Ayurveda. Even though the Central Council of Indian Medicine, the governing body that monitors the matters related to Ayurveda education, has imposed various educational norms and regulations, the standard of education has been a cause of concern in recent years. The mushrooming of substandard Ayurvedic colleges is the most important factor that is being held responsible for this kind of erosion in the standards. The present study is a mailed survey, which was carried out to evaluate the “Extent of exposure to basic clinical skills during BAMS course” as perceived by the sample groups of students and teachers drawn from 32 Ayurvedic educational institutions spread all over India. A methodically validated questionnaire was used as the tool in the study, to which 1022 participants responded. The study indicates that there are some serious flaws in the existing system of the graduate-level Ayurveda education. Since the Ayurvedic graduates play an important role in the primary healthcare delivery system of the country, governing bodies are required to take necessary steps to ensure the adequate exposure of the students to basic clinical skills. Along with the strict implementation of all the regulatory norms during the process of recognition of the colleges, introducing some changes in the policy model may also be required to tackle the situation
Community-engaged strategies to promote hepatitis B testing and linkage to care in immigrants of Florida
AbstractTo improve early identification and linkage to treatment and preventive services for hepatitis B virus (HBV) in persons born in countries with intermediate or high (>2%) HBV prevalence, the University of Florida Center for HIV/AIDS Research, Education, and Services (UF CARES) employed community-engaged strategies to implement the Hepatitis B Awareness and Service Linkage (HBASL) program. In this brief report, we present a summary of program components, challenges, and successes. Faith and community-based networks were established to improve HBV testing and screening and to increase foreign born nationals (FBNs) access to HBV care. A total of 1516 FBNs were tested and screened for hepatitis B. The majority were females (50.4%), Asians (62.8%), non-Hispanic (87.2%), and they also received post-test counseling (54.8%). Noted program advantages included the development of community networks and outreach to a large population of FBNs. The major challenges were institutional delays, pressures related to meeting program deliverables, and diversity within FBNs populations. Community health workers in the United States can replicate this program in their respective communities and ensure success by maintaining a strong community presence, establishing partnerships and linkage processes, developing a sustainability plan, and ensuring the presence of dedicated program staff
(3E,5E)-3,5-Bis(4-allyloxybenzylidene)-1-benzylpiperidin-4-one
In the title compound C32H31NO3, the allyloxy groups on either side of the piperidin-4-one ring are conformationally disordered. The contribution of major and minor components of the allyloxy group at the 3rd position of the ring are 0.576 (4) and 0.424 (4), respectively, and those at the 5th position are 0.885 (3) and 0.115 (3), respectively. The six-membered piperidin-4-one ring adopts a sofa conformation with the benzyl group occupying an equatorial position and the olefinic double bonds possessing an E configuration. Flanking phenyl substituents are stretched out on either side of the six-membered ring. π–π interactions with a centroid–centroid distance of 3.885 (1) Å give rise to molecular dimers and short C—H⋯π contacts lead to chains along the c axis
Gene action of blast disease reaction and grain yield traits in finger millet
Gene action of blast reaction, yield and yield associated traits in finger millet were studied using a 4x4 North Carolina Design II mating scheme. The four female and four male parents and their 16 crosses were evaluated at Alupe and Kakamega in western Kenya in a randomized complete block design under both artificially induced and natural disease pressure. General combining ability (GCA) and specific combining ability (SCA) estimates of the traits were calculated to determine the genotypes breeding value. The GCA variance predominated over SCA variance for all traits except finger width hence these traits can be improved through selection. With high, desirable GCA effects, male parent KNE 392 and female parents KNE 744 and IE 11 are suitable for blast resistance breeding while male parent Okhale 1 is suitable for grain yield improvement. The frequency distribution for the segregating F2 generation for the three blast types differed within and between crosses which could be due to differences in gene numbers or gene combinations being expressed in the different parents used. Convergent crossing or gene pyramiding for durable resistance could be possible
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