WordNet

to go or travel towards; "where is she heading"; "We were headed for the mountains"
the length or height based on the size of a human or animal head; "he is two heads taller than his little sister"; "his horse won by a head"
the pressure exerted by a fluid; "a head of steam"
the tip of an abscess (where the pus accumulates)
(nautical) a toilet on board a boat or ship
(usually plural) the obverse side of a coin that usually bears the representation of a persons head; "call heads or tails!"
a projection out from one end; "the head of the nail", "a pinhead is the head of a pin"
a single domestic animal; "200 head of cattle"
the striking part of a tool; "the head of the hammer"
the upper part of the human body or the front part of the body in animals; contains the face and brains; "he stuck his head out the window" (同)caput
a person who is in charge; "the head of the whole operation" (同)chief, top_dog
(grammar) the word in a grammatical constituent that plays the same grammatical role as the whole constituent (同)head word
a rounded compact mass; "the head of a comet"
a user of (usually soft) drugs; "the office was full of secret heads"
an individual person; "tickets are $5 per head"
that part of a skeletal muscle that is away from the bone that it moves
the foam or froth that accumulates at the top when you pour an effervescent liquid into a container; "the beer had a large head of foam"
the front of a military formation or procession; "the head of the column advanced boldly"; "they were at the head of the attack"
the rounded end of a bone that fits into a rounded cavity in another bone to form a joint; "the head of the humerus"
the top of something; "the head of the stairs"; "the head of the page"; "the head of the list"
be the first or leading member of (a group) and excel; "This student heads the class" (同)head up
be in charge of; "Who is heading this project?" (同)lead
be in the front of or on top of; "The list was headed by the name of the president"
form a head or come or grow to a head; "The wheat headed early this year"
remove the head of; "head the fish"
take its rise; "These rivers head from a mountain range in the Himalayas"
regulate housing in; of certain areas of towns (同)district
any of the regions of the surface of the Earth loosely divided according to latitude or longitude (同)geographical zone
(anatomy) any encircling or beltlike structure (同)zona
a locally circumscribed place characterized by some distinctive features
an area or region distinguished from adjacent parts by a distinctive feature or characteristic

PrepTutorEJDIC

(顔を含めた)『頭』,頭部,首;(髪の生えている部分の)頭 / 『頭脳』,頭の働き,知力,才能;理性 / 『長』,指導者,支配者 / (ある物の)頭,上部,先端,先頭 / (川・泉の)源,水源 / (人・動物の)頭数,一人,1頭 / 『首席』,首位 / 《複数形で》(頭像のある)貨幣の表 / 項目,表題(新聞の)見出し / 《米俗》マリファナ常用者 / 長の,指導者の / …‘の'先頭に立つ,‘を'率いる;…‘の'長である / (…の方へ)…‘を'向ける《+『名』+『for』(『toward』)+『名』》 / (サッカーで)〈ボール〉‘を'頭で受ける,ヘディングする / (…に向かって)進む《+for(toward)+名》・「give a head」で「オーラルセックスをする・相手の性器をなめる」
(何らかの目的・特徴などによって他の地域と区別された)『地帯』,地域,地区(belt, area) / (気候によって地球を大別した)帯(たい) / 《米》(交通・郵便などの)同一料金区域;(郵便番号で分けた)郵便区 / (環状の)ベルト,輪,帯 / …‘を'地帯(地区)に分ける / (…の目的に)〈地域〉‘を'区画規制する《+名+as(for)+名》 / …‘を'帯で巻く,‘に'帯印をつける
heliumの化学記号

UpToDate Contents

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1. 頭頸部皮膚切除における解剖学的危険部位 anatomic danger zones in cutaneous surgery of the head and neck
2. 頭頚部癌の診断および病期分類の概要 overview of the diagnosis and staging of head and neck cancer
3. 頭頚部癌の長期生存者に対するアプローチの概要 overview of approach to long term survivors of head and neck cancer
4. 頭頸部癌に対する治療の概要 overview of treatment for head and neck cancer
5. 幼児および小児における軽微な頭部外傷：評価 minor head trauma in infants and children evaluation

English Journal

Micro particle image velocimetry measurements of steady diastolic leakage flow in the hinge of a st. Jude medical(®) regent™ mechanical heart valve.

Jun BH1, Saikrishnan N, Yoganathan AP.Author information 1G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.AbstractA number of clinical, in vitro and computational studies have shown the potential for thromboembolic complications in bileaflet mechanical heart valves (BMHV), primarily due to the complex and unsteady flows in the valve hinges. These studies have focused on quantitative and qualitative parameters such as velocity magnitude, turbulent shear stresses, vortex formation, and platelet activation to identify potential for blood damage. However, experimental characterization of the whole flow fields within the valve hinges has not yet been conducted. This information can be utilized to investigate instantaneous damage to blood elements and also to validate numerical studies focusing on the hinge's complex fluid dynamics. The objective of this study was therefore to develop a high-resolution imaging system to characterize the flow fields and global velocity maps in a BMHV hinge. In this study, the steady leakage hinge flow fields representing the diastolic phase during the cardiac cycle in a 23 mm St. Jude Medical regent BMHV in the aortic position were characterized using a two-dimensional micro particle image velocimetry system. Diastolic flow was simulated by imposing a static pressure head on the aortic side. Under these conditions, a reverse flow jet from the aortic to the ventricular side was observed with velocities in the range of 1.47-3.24 m/s, whereas low flow regions were observed on the ventricular side of the hinge with viscous shear stress magnitude up to 60 N/m(2). High velocities and viscous shearing may be associated with platelet activation and hemolysis, while low flow zones can cause thrombosis due to increased residence time in the hinge. Overall, this study provides a high spatial resolution experimental technique to map the fluid velocity in the BMHV hinge, which can be extended to investigate micron-scale flow domains in various prosthetic devices under different hemodynamic conditions.
Annals of biomedical engineering.Ann Biomed Eng.2014 Mar;42(3):526-40. doi: 10.1007/s10439-013-0919-y. Epub 2013 Oct 2.
A number of clinical, in vitro and computational studies have shown the potential for thromboembolic complications in bileaflet mechanical heart valves (BMHV), primarily due to the complex and unsteady flows in the valve hinges. These studies have focused on quantitative and qualitative parameters s
PMID 24085344

Histological insights in iminodipropionitrile-induced toxicity in rats.

Ibrahim KE1, Khan HA2, Omer FA3.Author information 1Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia.2Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia. Electronic address: khan_haseeb@yahoo.com.3Diagnosis Center, Veterinary Research Institute, Animal Resources Research Corporation, Khartoum, Sudan.AbstractIminodipropionitrile (IDPN) is a prototype nitrile compound that produces excitation, chorea and circling (ECC) syndrome in rodents. Previous studies have implicated vestibular hair cell degeneration in IDPN-induced behavioral abnormalities. Although the pathological changes in vestibular labyrinth of IDPN-treated rats are well documented, the effects of IDPN on other organ systems are not clearly understood. We therefore examined the histopathological alterations in inner ear, brain, liver and kidneys of rats exposed to IDPN. Adult male Wistar rats were divided into two groups of six animals each. Control rats received normal saline whereas the IDPN group was treated with IDPN (100mg/kg, i.p.) daily for 7 days. All the animals were carefully observed for any behavioral abnormality and the dyskinetic movements including the vertical and horizontal head weaving, circling and backward walking were quantified. The animals were sacrificed on day 9 and the samples of cochlea, brain, liver and kidney were collected for histopathology. The results showed a direct correlation between the severity of behavioral deficits and the cellular damage in crista ampullaris in IDPN-treated rats. Histopathology of liver was severely influenced by IDPN treatment, leading to vacuolization of cytoplasm, distorted sinusoids, infiltration of mononuclear cells and necrotic zones. However, the severity of hepatic damage in IDPN-treated rats was independent of the magnitude of vestibular hair cell degeneration as well as the severity of behavioral deficits. Administration of IDPN in the vestibulotoxic doses did not produce any histological changes in the brain cortex and kidneys of rats.
Experimental and toxicologic pathology : official journal of the Gesellschaft für Toxikologische Pathologie.Exp Toxicol Pathol.2014 Mar;66(2-3):89-96. doi: 10.1016/j.etp.2013.11.004. Epub 2013 Dec 12.
Iminodipropionitrile (IDPN) is a prototype nitrile compound that produces excitation, chorea and circling (ECC) syndrome in rodents. Previous studies have implicated vestibular hair cell degeneration in IDPN-induced behavioral abnormalities. Although the pathological changes in vestibular labyrinth
PMID 24332269