Handle-theory and engulfing

1975 ◽  
Vol 78 (1) ◽  
pp. 111-116
Author(s):  
S. Buoncristiano
Keyword(s):  
Simple Procedure ◽  
Regular Neighbourhood ◽  
Ambient Isotopy ◽  
Closed Polyhedron

This paper is concerned with the engulfing of a polyhedron X from one end δ_ W of a cobordism (W, δ_ W, δ+W). In the case where the pair (W, δ_ W) is highly connected this version of Engulfing is dealt with in Rourke and Sanderson (2) by combining the method used in the proof of the h-cobordism theorem (eliminating handles) with a simple procedure involving handle-moves. A handle-move is an ambient isotopy which shrinks a handle H onto a small regular neighbourhood of its fibre D. Thus, if a closed polyhedron misses D, a handle-move can be applied to cause X to slip off H.

Targeting Platelets Containing Electro-encapsulated lloprost to Balloon Injured Aorta in Rats

1995 ◽  
Vol 73 (03) ◽  
pp. 535-542 ◽  
Author(s):  
N Crawford ◽  
A Chajara ◽  
G Pfliegler ◽  
B EI Gamal ◽  
L Brewer ◽  
...  
Keyword(s):  
Time Course ◽  
Therapeutic Potential ◽  
Simple Procedure ◽  
Rat Aorta ◽  
Balloon Injury ◽  
Post Injury ◽  
Antiproliferative Effects ◽  
Platelet Deposition ◽  
Total Dna ◽  
Novel Drug

SummaryDrugs can be electro-encapsulated within platelets and targeted to damaged blood vessels by exploiting the platelet’s natural haemostatic properties to adhere to collagen and other vessel wall constituents revealed by injury. A rat aorta balloon angioplasty model has been used to study the effect on platelet deposition of giving iloprost loaded platelets i.v. during the balloon injury. After labelling the circulating platelets with 111-Indium before balloon injury, time course studies showed maximum platelet deposition on the injured aorta occurred at about 1 h post-injury and the deposition remained stable over the next 2-3 h. When iloprost-loaded platelets were given i.v. during injury and the circulating platelet pool labelled with 111-Indium 30 min later, platelet deposition, measured at 2 h postinjury, was substantially and significantly reduced compared with control platelet treatment. Some antiproliferative effects of iloprost-loaded platelets given i.v. during injury have also been observed. Whereas the incorporation of [3H]-thymidine into aorta intima-media DNA at 3 days post injury was 62-fold higher in balloon injured rats than in control sham operated rats, thymidine incorporation into intima/media of rats which had received iloprost loaded platelets during injury was reduced as compared with rats subjected only to the injury procedure. The reduction was only of near significance, however, but at 14 days after injury the total DNA content of the aorta intima/media of rats given iloprost loaded platelets during injury was significantly reduced. Although iloprost loaded platelets can clearly inhibit excessive platelet deposition, other encapsulated agents may have greater anti-proliferative effects. These studies have shown that drug loaded platelets can be targeted to injured arteries, where they may be retained as depots for local release. We believe this novel drug delivery protocol may have therapeutic potential in reducing the incidence of occlusion and restenosis after angioplasty and thrombolysis treatment. Electro-encapsulation of drugs into platelets is a simple procedure and, using autologous and fully biocompatible and biodegradable platelets as delivery vehicles, might overcome some of the immunological and toxicological problems which have been encountered with other delivery vectors such as liposomes, microbeads, synthetic microcapsules and antibodies.

Visualizing 3D Molecular Structures Using an Augmented Reality App

2019 ◽  
Author(s):  
Kristina Eriksen ◽  
Bjarne Nielsen ◽  
Michael Pittelkow
Keyword(s):  
Augmented Reality ◽  
Small Molecules ◽  
Computer Modelling ◽  
Simple Procedure ◽  
3D Structure ◽  
Molecular Structures ◽  
Free Software ◽  
Programming Skills ◽  
2D Space ◽  
Made In

<p>We present a simple procedure to make an augmented reality app to visualize any 3D chemical model. The molecular structure may be based on data from crystallographic data or from computer modelling. This guide is made in such a way, that no programming skills are needed and the procedure uses free software and is a way to visualize 3D structures that are normally difficult to comprehend in the 2D space of paper. The process can be applied to make 3D representation of any 2D object, and we envisage the app to be useful when visualizing simple stereochemical problems, when presenting a complex 3D structure on a poster presentation or even in audio-visual presentations. The method works for all molecules including small molecules, supramolecular structures, MOFs and biomacromolecules.</p>

Urease as a Possible Tracer for Sewage Effluent Plumes

1989 ◽  
Vol 21 (2) ◽  
pp. 93-97 ◽  
Author(s):  
R. Sadler
Keyword(s):  
Urease Activity ◽  
Simple Procedure ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Particulate Phase ◽  
Untreated Sewage ◽  
Potential Alternative ◽  
Two Parameters ◽  
Point Source Discharges

The suitability of sedimentary urease activity as a potential tracer for sewage outfall plumes has been examined. Enzyme activity is readily measured in the sediments by a relatively simple procedure and results may be obtained within a few hours of sampling. The results of urease measurements in areas around point source discharges were compared with bacteriological data for the same areas. Three areas were selected for study: a discharge of untreated sewage into a harbour, a discharge from a sewage treatment plant to a river and a discharge from a contaminated drain to a small beach. In all cases, positive correlation between the distribution of the two parameters was observed. Urease activity probably reflects the movement of soluble products from the outfall whereas E.coli represents the particulate phase of the discharge. Although further work will be required, urease activity does offer a potential alternative to E.coli for tracing plumes of faecal pollution.

The rein-type arthroscopic capsular suture for triangular fibrocartilage complex foveal tears: midterm results for 90 patients

2021 ◽  
pp. 175319342110241
Author(s):  
I-Ning Lo ◽  
Kuan-Jung Chen ◽  
Tung-Fu Huang ◽  
Yi-Chao Huang
Keyword(s):  
Simple Procedure ◽  
Distal Radioulnar Joint ◽  
Triangular Fibrocartilage Complex ◽  
Joint Stability ◽  
Level Of Evidence ◽  
Radioulnar Joint ◽  
High Satisfaction ◽  
Ultrasound Assessment ◽  
Triangular Fibrocartilage

We describe an arthroscopic rein-type capsular suture that approximates the triangular fibrocartilage complex to the anatomical footprint, and report the results at a minimum 12 month follow-up. The procedure involves two 3-0 polydioxanone horizontal mattress sutures inserted 1.5 cm proximal to the 6-R and 6-U portals to obtain purchase on the dorsal and anterior radioulnar ligaments, respectively. The two sutures work as a rein to approximate the triangular fibrocartilage complex to the fovea. Ninety patients with Type IB triangular fibrocartilage complex injuries were included retrospectively. The 12-month postoperative Modified Mayo Wrist scores, Disabilities of Arm, Shoulder and Hand scores and visual analogue scale for pain showed significant improvements on preoperative values. Postoperative range of wrist motion, grip strength and ultrasound assessment of the distal radioulnar joint stability were comparable with the normal wrist. The patients had high satisfaction scores for surgery. There were minor complications of knot irritation. No revision surgery for distal radioulnar joint instability was required. It is an effective and technically simple procedure that provides a foveal footprint contact for the triangular fibrocartilage complex. Level of evidence: IV

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