233 research outputs found
Cost effectiveness of bio-ethanol to reduce carbon dioxide emissions in Greece
The purpose of this study is to evaluate ethanol cost- effectiveness with regards to carbon dioxide emissions. Actually, bio-fuel production is only viable thanks to the tax credit policy resulting in economic âdeadweightâ loss. The environmental performance is assessed under the Life Cycle Assessment (LCA) framework. Economic burden to society to support the activity divided by avoided CO2 equivalent emissions indicates the bio-ethanol cost effectiveness. Agricultural feedstock supply that comprises of sugarbeets, grains and industrial processing sub-models are articulated in a regional sector model. The maximization of total welfare determines optimal crop mix for farmers and the best configurations for industry. This is illustrated for bio-ethanol produced by the ex-sugar industry in Thessaly, Greece. Life cycle activity analysis showed that, at the optimum, CO2 emission is reduced between 1 and 1.5 t of carbon dioxide equivalent per ton of ethanol. The unitary cost falls in the range of 100 to 250 euro per ton of CO2 and it is remarkably dependent on the agricultural policy scenario.Cost effectiveness, ethanol, mathematical programming, life cycle assessment, greenhouse gases
A prefix brachial plexus with two trunks and one anterior cord
The brachial plexus presents a great variability in formation, division and branching pattern. Its variants are of immense importance during axillary and arm surgery and nerve blockade.
The current case highlights a unilateral atypical formation of brachial plexus, the so called prefix, in which the C4 root contributed a large branch to the superior trunk and further anastomosis with the inferior trunk. Thus, the prefix or high brachial plexus consisted of a superior and inferior trunk and one anterior cord.
Coexisting neural and arterial variations are also discussed in relation to the data literature
Anatomic variability in the relation between the retromandibular vein and the facial nerve: a case report, literature review and classification
Knowledge of anatomic variations concerning head and neck veins is important to surgeons performing interventions in these regions, as well as to radiologists. The retromandibular vein is used as a guide to expose the facial nerve branches inside the parotid gland, during parotid surgery and open reduction of mandibular condyle fractures. It is also used as a landmark for localisation of the nerve and compartmentalisation of parotid gland lesions preoperatively, during computed tomography, magnetic resonance imaging and sonography. In this paper, the anomalous retromandibular veinâs course on the left side of a male cadaver is described. The vein was formed around the nerve, while the maxillary vein travelled medial to the facial nerve branches and superficial to the superficial temporal vein. Interestingly, the facial nerve temporofacial division crossed again the superficial temporal vein upwards, forming a ânerve forkâ. The incidence of the reported variability of the relationship between the retromandibular vein and the facial nerve are discussed with a detailed literature review. Accordingly, the typical deep position of the retromandibular vein in relation to the facial nerve is estimated to 88.17% to all sides. Furthermore, an updated classification system is proposed, including 4 types and subtypes
A rare cadaveric finding of ectopic origin of a bronchial artery: surgical and imaging consequences
Bronchial arteries arise normally directly from the descending thoracic aorta, at the level between the fourth and sixth thoracic vertebra. However the anatomical variations are very frequent regarding the origin or the number of branches. We present a rare cadaveric finding of an ectopic right bronchial artery originating from the right subclavian artery through common stem with the right internal thoracic artery and we discuss the clinical significance of this finding. A 72-year-old formalin-embalmed male cadaver was dissected during a routine anatomical course. The right bronchial artery originated from the right subclavian artery with a common stem with the right internal thoracic artery. Although ectopic origin of the right bronchial artery from the right internal thoracic artery is rare, recognition of this anatomical variation is important in bronchial embolization due to hemoptysis, in coronary bypass grafting and in lung transplantation
Co-existence of os acromiale with suprascapular osseous bridge: a case report and review of the literature
We report on a very rare case of co-existence of os acromiale with suprascapular
osseous bridge in a dry scapula. The frequency of os acromiale alone ranges
from 1.3 to 15%, while the frequency of suprascapular osseous bridge varies
between 0.036% and 12.5%. We review the relative literature and emphasize
the fact that such knowledge is important for a physician in order to avoid
misdiagnosis of an acromion fracture and lytic lesion of the scapula
A coexisting anatomic variation of median and ulnar nerves in a cadaver palm
During a routine dissection we observed an anatomical variation of the median nerve and an atypical anastomosis in the palm region of a male cadaver. There were four distinct recurrent motor branches of the left median nerve and the palmar cutaneous branch of the ulnar nerve communicated directly with the third common palmar digital nerve. The presence of such anatomical variant in the hand should keep surgeons alert in the management of hand pathology especially in carpal tunnel syndrome which is a routine operation for many medical centers
Bilateral double testicular arteries: a case report and review of the literature. Potential embryological and surgical considerations
The aberrancies concerning the number, origin and course of the testicular arteries are found in an incidence of approximately 4.7â20% in the literature and are documented less frequently than the respective variations of the homonymous veins. In the current study, a very rare complex of testicular arteriesâ variations isdescribed, in which the occurrence of bilateral double testicular arteries is recorded. Particularly, apart from the normal testicular arteries on each side, we observed an additional right testicular artery originated from the ipsilateral renal artery and an additional left testicular artery taking its origin from the abdominal aorta just above the renal arteryâs origin site; the latter additional testicular artery arched above the left renal vein. Both, the bilateral double testicular arteries accompanied the testicular vein on each side as their satellite arteries. We discuss the potential embryological development of that complex of arterial variants, their likely clinical and surgical applications, as well as we proceed on a brief review of the relevant literature
Anastomotic loop between common hepatic artery and gastroduodenal artery in coexistence with an aberrant right hepatic artery
Anatomical variations of the hepatic arteries are not uncommon. The anomalous hepatic arterial supply is of paramount importance in hepatobiliary, pancreatic or liver transplantation and in laparoscopic surgery. We describe an unusual case of a 66-year-old Greek male cadaver, where a rare anastomosis (in the form of an enlarged arterial loop, 4.84 mm in diameter) between the common hepatic artery (6.42 mm) and the gastroduodenal artery (GDA) (4.82 mm) coexisted with an aberrant right hepatic artery (ARHA) (6.38 mm) originating from the superior mesenteric artery. The proper hepatic artery was absent. The ARHA followed a route posterior to the portal vein and the common hepatic duct, entering the liver and supplying the right hepatic segment. A hypoplastic right gastric artery emanated from the GDA. Our case report highlights the combined variations of hepatic arteries and possible anastomoses emphasizing that a thorough knowledge of the classic and variable hepatic arterial anatomy are mandatory for surgeons and radiologists performing hepatic surgery and arteriography to avoid potential iatrogenic injuries in hepatobiliary and pancreas area and further medico-legal implications
High origin of a superficial ulnar artery arising from the axillary artery: anatomy, embryology, cinical significance and a review of the literature
The superficial ulnar artery (SUA) is an ulnar artery of high origin that lies superficially
in the forearm. Its reported frequency ranges from 0.17% to 2%. During
anatomical dissection in our department we observed a unilateral case of SUA in
a 75-year-old white male human cadaver. It originated from the right axillary
artery at the level of the junction of the two median nerve roots and followed
a looping course, crossing over the lateral root of the median nerve and running
lateral to it in the upper and middle thirds of the arm, whereas in the inferior
third of the arm the SUA crossed over the median nerve and ran medially to it. In
the cubital fossa, it passed superficially over the medial side of the ulnar aponeurosis
and coursed subcutaneously in the ulnar side of the forearm superficially
to the forearm flexor muscles. In the hand the SUA anastomosed with the
superficial palmar branch of the radial artery, creating the superficial palmar
arch. Additionally, it participated in the development of the deep palmar arch.
The axillary artery, after the origin of the SUA, continued as the brachial artery
and divided into the radial and common interosseous arteries in the cubital fossa.
The normal ulnar artery was absent. No muscular or other arterial variations
were observed in this cadaver. The embryological interpretation of this variation
is difficult and it may arise as a result of modifications to the normal pattern of
capillary vessel maintenance and regression. The existence of a SUA is undoubtedly
of interest to the clinician as well as to the anatomist. This report
presents a case of unilateral SUA along with a review of the literature, embryological
explanation and analysis of its clinical significance
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