1,721,082 research outputs found
Natural resins: chemical constituents and medicinal uses
Plants and their exudates are used worldwide for the treatment of several diseases and novel drugs continue to be developed through phytochemical research. There are more than 20,000 species of high vegetables, used in traditional medicines that are sources of potential new drugs. Following the modern medicine and drug research advancing, chemically synthesized drugs have replaced plants as the source of most medicinal agents in industrialized countries. However, in developing countries, the majority of the world’s population cannot afford pharmaceutical drugs and use their own plant based indigenous medicines. Several exudates from plants are well-known in folk medicine since ancient time, and they are today employed also for practical uses.
Dragon’s blood is a deep red resin, which has been used as a famous traditional medicine since ancient times by many cultures. Dragon's blood is a non-specific name for red resinous exudations from quite different plant species endemic to various regions around the globe that belong to the genera Dracaena (Africa) and Daemonorops (South-East Asia), more rarely also to the genera Pterocarpus and Croton (both South America). Dracaena draco L. is known as the dragon’s blood tree, and it’s endemic to the Canary Islands and Morocco. Phytochemical studies of resins obtained from incisions of the trunk of D. draco, have led to the isolation of flavans, along with homoisoflavans, homoisoflavones, chalcones and dihydrochalcones. Dragon’s blood has been used for diverse medical applications in folk medicine and artistic uses. It has astringent effect and has been used as a hemostatic and antidiarrhetic drug.
Frankincense, also known as Olibanum, is an old-known oleogum resin obtained from the bark of trees belonging to the genera Boswellia. There are 43 different reported species in India, Arabian Peninsula and North Africa. The importance of these plants is related to the use of extracts and essential oils of resin in traditional medicine like Ayurvedic and Chinese. Extracts from B. serrata resin are currently used in India for the treatment of rheumatic diseases and ulcerative colitis. Furthermore, extracts and essential oils of frankincense have been used as antiseptic agents in mouthwash, in the treatment of cough and asthma and as a fixative in perfumes, soaps, creams, lotions and detergents. In ancient Egypt the resin was used in mummification balms and unguents. Today frankincense is one of the most commonly used resins in aromatherapy. The biological activity of frankincense resins is due to the pentacyclic triterpenic acids, α- and β- boswellic acids and their derivatives, which showed a well documented anti-inflammatory and immunomodulatory activities.
Manna is an exudate from the bark of Fraxinus trees (Oleaceae). Originally it was only collected from trees with damaged bark, but later in southern Italy and northern Sicily plantations were established for manna production, in which the bark is intentionally damaged for exudation and collection of manna. In July-August a vertical series of oblique incisions are made in the bark on alternate sides of the trunk. A glutinous liquid exudes from this cut, hardens as it oxidises in the air into a yellowish crystalline mass with a bittersweet taste, and is then harvested. Manna is still produced in Sicily, mainly in the Castelbuono and Pollina areas, from Fraxinus ornus and Fraxinus angustifolia trees. The main component of manna is mannitol; it also contains glucose, fructose, maltotriose, mannotetrose, minerals and some unknown constituents. Manna is a mild laxative and an excellent purgative, it is suitable in cases of digestive problems, in atonic or spastic constipation. It’s useful as expectorant, fluidifier, emollient and sedative in coughs; as a decongestant in chronic bronchitis, laryngitis and tonsillitis; in hypertonic solutions it acts as a dehydrating agent in the treatment of wounds and ulcers. It can be used as a sweetener in cases of diabetes as it does not affect glycemia levels or cause glycosuria; in addition it is also a cholagogue as it promotes the flow of the contents of the gall bladder and bile ducts and so stimulates bile production
Tibial tubercle osteotomy: effect of different osteotomy planes on contact surface area and tubercle anteriorization
In 1983, Fulkerson introduced a technique of tibial tubercle osteotomy performed according to an inclined plane with respect to frontal plane. Due to obliquity of the osteotomy plane, this procedure allows both anterior and medial transfer of the tibial tubercle. The purpose of the study was to investigate the influence of the different degrees of the oblique plane of osteotomy on anterior displacement and the contact surface area of tibial tubercle. Synthetic bones were used for the study. An osteotomy of the tibial tubercle (TT) was performed in each specimen. Specifically, 3 different degrees of osteotomy planes relative to the reference frontal plane were examined: 20°, 30° and 40°. On each sample, tibial tubercle medial transposition of 5 mm, 10 mm and 15 mm was performed. Anterior displacement was measured with a caliper. Further, the bone contact surface was calculated for each sample and each transposition. Finally, the measured data were statistically compared with a geometric model. At 5 mm of medial TT transposition, the anterior displacement (AD) was 0.1 mm when the osteotomy was performed at 20°. It increased of 1.5 mm and 2.7 mm, respectively at 30° and 40°. At 15 mm of TT transposition, the AD was 3.4 mm at 20°, 7.6 mm at 30° and 10.0 mm at 40°. Concerning the amount of medialization, it was observed a decrease in the overall contact surface passing from 5 to 15 mm of TT transposition. In addition, regarding the oblique plane of the osteotomy, it was observed an increase in the contact surface area passing from 20° to 40°. The main result of the present study is that the amount of anteriorization and medialization of the tibial tubercle could be predicted by the degrees of oblique plane of osteotomy. An increase in medialization significantly reduces the contact surface area at low degrees of osteotomy plane, potentially increasing the risk of non-union
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Giant enchondroma recurrence of the proximal phalanx of the fifth finger: A case report
Enchondroma (EC) is a benign and cartilage-forming tumor that causes intramedullary lesions. Moreover, EC is the most common bone tumor in the phalanges and metacarpal bones of the hand, deforming the structure and causing pain and functional limitation. The management of this neoplasia is the surgical treatment and the approach that is well-accepted consists in the curettage followed by the void augmentation with biological or synthetic fillers. The results from surgery are usually good and the recurrence rate is low (2-15%). In this article we report a case of EC recurrence of the proximal phalanx of the fifth finger of the hand after curettage and grafting. The patient was treated with the amputation of the fifth ray according to the Tsuge technique, obtaining a satisfying clinical result
Atractyligenin chemistry. Part 4: Synthesis of the 15β-ol epimer of atractyligenin
The oxidation with PCC of atractyligenin 3, the aglicone of the toxic glycoside 1 isolated from Atractylis gummifera L., led to the 15-oxo-derivative 6, together with a small amount of 2,15-dioxoderivative 5, with a selective oxidation of the allylic 15-OH group of the molecule. Further reduction with NaBH4 and KOH hydrolysis gave stereoselectively the 15β-ol epimer of atractiligenin 9
RAPID DETERMINATION OF VOLATILE CONSTITUENTS OF PHILLYREA LATIFOLIA L. BY GAS CHROMATOGRAPHY-MASS SPECTROMETRY WITH SOLID- PHASE MICROEXTRACTION.
Dispelling the Myths Behind First-author Citation Counts
We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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