Opaque Oil Research Articles

Clouding of intraocular silicone oil in the absence of emulsification.

To describe intraocular clouding of silicone oil in the absence of emulsification. Retrospective observational case series of patients who received silicone oil injections and developed silicone oil discoloration without emulsification after pars plana vitrectomy. Clinical examinations and physicochemical analyses were performed to find out the common cause for the opaque oil. Thirteen patients developed silicone oil discoloration after pars plana vitrectomy. It could be traced down that all patients had received silicone oil from one respective production batch. The silicone oil was removed as soon as possible after the changes were detected (range, 8-16 weeks). Gas chromatography flame ionization detector (GC-FIC), size exclusion chromatography (SEC) and high performance liquid chromatography (HPLC) analysis showed the absence of small molecular weight compounds in the opaque lot. Thermogravimetric analysis (TGA) revealed the opaque lot was more temperature stable. During the follow-ups, no obvious retinal toxicity could be observed and best recorded visual acuity improved considerably in twelve patients and was only limited by the underlying retinal pathology. This is the first report on opacification of intraocular silicone oil without emulsification. This discoloration of silicone oil may disturb vision and prevent proper fundus examination, however, seems to be a non-toxic phenomenon without serious long-term consequences.

석유생산 시 유동안정성 확보를 위한 불투명 오일의 왁스생성온도 결정 연구

석유생산 시 유동안정성 확보를 위한 불투명 오일의 왁스생성온도 결정 연구

Tunable liquid iris actuated using electrowetting effect

A configuration for a tunable liquid iris, which consists simply of two immiscible liquids and two flat indium tin oxide (ITO) glass substrates, is proposed. The two immiscible liquids are transparent salt solution and opaque oil, respectively. The top ITO electrode was precoated with a 2-μm-thick polydimethylsiloxane film as the dielectric layer, while the surface of the bottom electrode was specially treated using ultraviolet irradiation to define specific hydrophilic regions. The iris aperture’s diameter could easily be regulated by varying the direct current bias voltages between the two electrodes. Results show that the aperture diameter can be continuously varied from 1.5 mm at the voltage-off state to 3.5 mm at a bias of 350 V. This liquid iris takes the advantages of low fabrication cost, fast response time, low-power consumption, and easy reversibility without the need of any mechanical movable parts.

Electrowetting-Based Liquid Iris

In this letter, we propose a liquid iris based on electrowetting. A dyed liquid is filled in a hollow cylinder cell. One substrate surface of the cell is coated with a Teflon layer. Due to the low surface tension of the Teflon, the dyed liquid forms a circular ring around the cylinder wall. The outside space of the liquid is filled with opaque oil. The opening of the circular liquid forms an aperture. When a voltage is applied to the cell, the dyed liquid shifts to the center of the ring due to electrowetting effect. Thus the aperture shrinks. Our results show that the aperture can be tuned between ${\sim}{5.0}$ and ${\sim}{\rm 2.8}~{\rm mm}$ . The device can provide reasonable response time. In the opening area, the transmittance was measured to be ${\sim}{86\%}$ .

Laser removal of lubricating oils from metal surfaces

This work analyzes the laser cleaning process used to remove lubricating oil from metal surfaces. In an experiment, mineral oil is removed from carbon steel, stainless steel, or copper surfaces using near-infrared (Nd:YAG) laser pulses that are weakly absorbed by the oil. The results are compared with those from a strongly absorbing case in which a commercial lubricant is removed from carbon steel surfaces using ultraviolet (excimer) laser pulses that are relatively strongly absorbed by the lubricant. The removal process is visualized using laser flash shadowgraphy. Numerical computations are conducted to estimate the temperatures of the oil and substrate, and the results are discussed in comparison with the experimental data. The removal mechanism has been found to depend critically on the optical properties of the oil. In the case of Nd:YAG laser cleaning where the oil is almost transparent to the incident laser beam, it is effectively removed by the laser pulses. The removal efficiency is independent of the oil film thickness up to 150μm, revealing that the removal occurs by explosive vaporization of the oil at the oil–substrate interface followed by bulk hydrodynamic flow. On the other hand, removal of an opaque oil film is well explained using a surface ablation of organic ingredients in which the removal rate is substantially lower than the removal rate under the explosive vaporization mechanism. The optimal conditions for oil removal are discussed based on the experimental results.

해저 석유 생산시스템 내 유동안정성 확보를 위한 불투명 오일의 왁스생성온도 측정법

비교적 접근이 용이한 육상 및 천해에서 석유의 생산은 이미 완료되었거나 대부분이 진행 중이기에 석유 생산 지역이 점차 심해로 확장되고 있다. 심해와 같은 저온환경에서 석유생산이 이루어지면 석유의 부존환경과 다른 온도와 압력에 노출되어 생산시스템에 다양한 고형물이 집적되어 석유가 안정적으로 생산되지 못하게 하는 유동안정성 확보 문제가 발생할 수 있다. 고형물 중 왁스는 온도에 민감하기때문에 왁스의 집적을 예측하고 제어하기 위해서는 오일 내 왁스가 석출되기 시작하는 온도인 왁스생성온도의 정확한 측정이 요구되나 표준화된 측정법이 존재하지 않아 다양한 방법이 제안되고 있는 실정이다. 이 연구에서는 점도측정법, 시차주사열량법, 필터막힘점측정법, 압력필터측정법을 적용하여 불투명 오일의 왁스생성온도를 측정하고, 이를 검증하기 위해 고형물생성유도장치와 가스크로마토크래피를 이용하였다. 이 연구결과를 통해 오일특성에 따른 왁스생성온도 실험법을 체계화한다면 불투명 오일의 왁스 생성온도 측정법 표준화하는데 주요자료로 이용할 수 있어 왁스에 의한 유동안정성 확보 문제를 예측하고 해결하는데 활용될 수 있을 것이다.

Ultra-High Transmission Electrowetting Displays Enabled by Integrated Reflectors

A reflector technique for increasing the transmission performance of a back-lit electrowetting display is presented. The electrowetting display pixel structure consists of an opaque oil film that blocks light transmission. Electrowetting with 5-10 V breaks up the oil film and creates a transmissive area for the pixel. With real-world electrowetting materials and device constraints, the transmissive area typically reaches 60% to 80% of the pixel area. By integrating a simple thin-film reflector between the backlight and the remaining oil film area, the effective transmission can be boosted to >90%. This high efficiency is promising for battery-powered applications and for high-brightness sunlight-legible displays.

Evolutionary behaviour of miniemulsion phases: II. Growth mechanism of miniemulsion droplets

The growth mechanism of droplets of hexadecane-in-water emulsions stabilized by heptaethylene glycol mono-n-dodecyl ether was studied by means of photon correlation spectroscopy. When the water-to-oil ratio (WOR) was varied from 4 to 10, a translucent oil in water emulsion (a so-called `miniemulsion') was obtained, while an opaque oil in water emulsion (O/W emulsion) was prepared when WOR was equal to 3. The z-average hydrodynamic radius of droplets, rz, was measured over the 24 days after preparation. Plotting the cube of the z-average radius as a function of time, we found that r 3z varies linearly with time in the system of the O/W emulsion (WOR = 3). This suggests that the process by which the droplets grow is that of Ostwald ripening. On the other hand, the same plot for the system of miniemulsions (4 < WOR < 10) shows two regimes in the process. In both regimes, r 3z varies linearly with time. The rate obtained for the earlier stage is smaller than that of the latter stage. The droplet size distribution became too broad compared with the prediction of Lifshitz-Slezov-Wagner theory for Ostwald ripening ~10 days after preparation. Then it approached the predicted distribution again ~20 days after preparation.

Instrumentation to measure the oil thickness on a wavy water surface

The instrumentation developed to measure the thickness of an oil layer on water in the presence of waves is described. It consists of a probe which follows the surface of water; a light-sensitive gauge attached to the probe measures the extent to which it is submerged in opaque oil, thus determining the oil thickness. In transparent petroleum products motion pictures may be used for this purpose. The results of performance tests of components and the preliminary tests on actual waves are presented.

Spezielle neurologische Untersuchungsmethoden

This is apparently a companion volume to an extensive treatise on general neurology in preparation by Professor Schaltenbrand of Wurzburg. He and Bammer describe the techniques for obtaining and studying cerebrospinal fluid. Most useful is a four-page table which compares values of the various physical and chemical components of lumbar spinal fluid and blood serum. There is rather more than usual detail concerning the variety of colloidal reactions used in various countries. Roentgen investigation of the skull (Nadjmi and Schwind) is given much more emphasis than that of the spinal column. Pneumography and angiography are illustrated in detail. The reproduction of the angiograms is not as good as usual, and there is reversal of figures and legends for cisterns of the brain in Fig 47b and c. Myelography is only briefly described, with a picture of a special needle and catheter for removing opaque oil the day after the study

Total myelography with radiopaque emulsions.

Myelography continues to be the basic and essential procedure for the diagnosis of abnormalities of the spinal cord and canal. The shortcomings of the procedure as currently performed are due, in large measure, to the inadequacies of the contrast media. Our experimental studies with various radiopaque emulsions are the subject of this report. Air was the original contrast medium, introduced by Dandy (1) in 1919. Air myelography does not require fluoroscopic manipulation and the air is completely absorbed. However, a large number of inconclusive examinations due to the relatively poor contrast qualities of air and the high percentage of complicating severe headaches have severely limited its use. Positive contrast myelography with iodized oil (Lipiodol) was introduced in 1922 by Sicard and Forestier (2). Although visualization was satisfactory, the medium was too dense, tended to break up into droplets, and was extremely difficult to remove from the spinal canal. Chronic meningeal irritation frequently resulted from the retained oil. Fluoroscopic manipulation was required for moving the oil column. Pantopaque, a less viscous insoluble synthetic oil, was introduced in 1944 (3, 4). It also is practically nonabsorbable and irritating to the meninges if retained, but it is more easily removed because of its lower viscosity. Pantopaque is now the standard myelographic medium in the United States. The shortcomings of conventional myelographic media are obvious and it is readily apparent that the ideal myelographic medium has not been devised. The theoretical criteria of such a medium would be (a) thorough miscibility with the spinal fluid allowing for total opacification of the spinal subarachnoid spaces, (b) satisfactory density which would permit opacification of the spaces and visualization of the cord mass, (c) no toxicity, and (d) complete absorption and elimination of the medium. Theoretically, three types of media are miscible with the spinal fluid and will produce total opacification of the spinal subarachnoid space. These are water-soluble agents, aqueous suspensions of finely divided opaque particles, and emulsions of an opaque oil in water. Water-soluble media: In 1931 Arnell and Lidström (5) introduced water-soluble abrodil (Skiodan) in Sweden. Several other water-soluble preparations have subsequently been tried. Regardless of the chemical structure of the soluble medium, the solution must contain sufficient solute to be adequately radiopaque; this requires a concentration which makes the solution strongly hypertonic and therefore irritating to the meninges. In addition, the chemical nature of the material also contributes to meningeal irritation. The water-soluble preparations, however, are all rapidly absorbed.

Experimental Studies with a New Radiopaque Emulsion

A long and generally unsuccessful search has been made for a safe radiopaque colloid or emulsion to be employed in intravenous hepatosplenography. We should like to report our recent experiences in the development and experimental use of such an agent, as well as its apparent benefit in a number of other fields of contrast radiography. The most widely used colloid has been Thorotrast, a 25 per cent colloidal suspension of thorium dioxide. Although it produces a satisfactory opacification of the liver and spleen, it has been almost completely abandoned because it is radioactive and has been shown to produce malignant tumors secondary to its permanent deposition and long half-life, at least 50 such cases having been reported (1, 2, 3). Preparations of nonradioactive, insoluble, heavy-metal salts such as barium sulfate (4), zinc, and tantalum oxide (5) have been prepared and tested. These have been suspensions rather then true colloids and, because of their subsequent instability and large particle size, have proved unsatisfactory. Theoretically, an emulsion of an opaque oil should have many of the advantages of Thorotrast and should also be capable of being metabolized and removed from the body. In 1938 Degkwitz (6) published his experiments with such an emulsion, but no subsequent reports have come from his laboratory. Our current preparation is a 50 per cent emulsion of Ethiodol in 5 per cent glucose. It has been stable for periods of up to six months and can be heat-sterilized. It cannot, however, be autoclaved. Many emulsifying agents have been tested, and at the present time we are using lecithin and pluronic acid. These have produced a satisfactory emulsion, particularly when prepared by a special reversal process. This, in brief, entails the making of an initial water-in-oil emulsion and reversing it by chemical means to an oil-in-water type. Full details of the exact preparation technic will be given in a later publication.2 The principal properties of the final Ethiodol emulsion are as follows: 1. It can be prepared with an oil concentration as high as 60 per cent. 2. The average oil particles are about 0.3 micron in size. 3. It is freely miscible with aqueous media, and, therefore, with all body fluids. 4. It is stable for long periods. 5. The Ethiodol particles, being insoluble, are relatively inert chemically and do not react appreciably with the tissues. 6. It can be heat-sterilized. 7. It can be diluted to a low oil concentration without physical alteration. 8. The emulsion is almost isotonic and will not affect osmotic phenomena. 9. The Ethiodol, after intravenous injection and deposition in the liver and spleen, is eliminated in a relatively short period of time (approximately two to seven days). 10. The emulsion has a viscosity lower than Ethiodol. 11. The emulsion has the property of adhering to raw, irregular, or diseased surfaces.

The Technique of Sialography

The differential diagnosis of swellings of the side of the face and neck has never been easy and one would have thought that, as soon as radiological methods were available, attention would have been given to the application of X-ray investigation to such structures in those parts that lend themselves to the method. Elimination of diseases of the salivary glands would considerably clarify the diagnostic field. A survey of the literature suggests that it was not until 1913 that an attempt was made to demonstrate the parotid duct, when it is believed that Arcelin endeavoured to do so with a bismuth suspension; confirmation of this is lacking. It seems probable that, at that time, insufficient attention had been given to the question of an appropriate opaque medium and lack of such, apparently, led to the belief that this investigation was impracticable. It is interesting to note that, in practice, there was already an appropriate medium, for, in 1896, Winternitz had introduced Iodipin, a chloro-iodised oil, for therapeutic purposes (this is still manufactured by Merck), while in 1901 Lafay had prepared a purely iodised oil for therapeutic purposes which was manufactured under the name of Lipiodol. The chemical characteristics and radiological uses of these contrast oils are well known, but, as a matter of fact, Lipiodol was not used as X-ray contrast material until 1921 when Sicard and Forestier first put it to this use. There is still some doubt as to who first used opaque oil for sialography.

Bilateral bronchography; new material and technic.

Because of the more stringent requirements of modern chest surgery, complete bilateral bronchograms are requested more frequently than a few years ago. This prompts a re-evaluation of the contrast media now available and of the technics employed in the complete mapping of the bronchial tree. For many years, iodized oils have remained the opaque materials of choice. These are usually well tolerated, but their disadvantages become apparent when the opaque oil droplets, retained in the terminal bronchioles or in the alveoli, interfere with further examination of the lungs or when some patient proves allergic to iodine. Both of these disadvantages are enhanced when the injection involves the entire bronchial tree. To avoid the persistent “lung stain” of iodized oils, some European workers have been using water-soluble absorbable iodine preparations (3). These preparations are absorbed very rapidly, usually in a few minutes, and do not cause any persistent lung opacity. The very speed of absorption, however, increases the dangers of iodine sensitivity and makes the examination a hurried procedure. Aqueous preparations have the further disadvantage of being much more irritating to the bronchial mucosa than iodized oils. For this reason, the examination requires a larger amount of anesthetic, and this increases the danger from cocaine or its derivatives. It is probably best to limit the use of water-soluble media to the injection of a small bronchial territory and to record the fleeting visualization on spot films. Along with water-soluble contrast media, English workers have developed a slowly absorbable preparation called Dionosil oily. This medium has been used for about two years in England and South America, and reports have been uniformly favorable (1, 2). Our experience (involving 25 bilateral bronchograms) parallels that of others. Dionosil oily is a 50 per cent suspension of the crystals of n-propyl ester of 3:5-diiodo-4-pyridone-N-acetic acid in arachis oil. The opacity is similar to that of the iodized oils. The new preparation, however, is absorbed in three to five days, leaving no “lung stain.” The injection of Dionosil oily is no more irritating than that of iodized oil and requires no more anesthetic. Probably because of the size of the crystals, Dionosil does not penetrate the terminal bronchioles nor the alveoli, and most of the material is expelled by coughing. The remaining material is absorbed after hydrolyzation without liberation of free iodine. This makes it possible to employ Dionosil even in iodine-sensitive patients. Regardless of the contrast medium employed, the technic of injection should also be reviewed for greater reliability and ease of performance. Ordinarily, complete bilateral bronchograms are obtained by the successive employment of multiple positions. For best results, this method requires pot-filming of each bronchial territory as it is filled.

Bronquiectasias.

This monograph, one of the<i>Manuales de Medicina Practica</i>, gives a vivid description of the clinical types of bronchiectasis seen in Argentina, including roentgenographic observations and discussions of the physiopathology of the disease, certain pathologic features and therapeutic methods. The structure of the bronchi was studied by bronchography with opaque oil, by tomography and by a special photographic technic called "broncorrelievografía," by which means minute details of the bronchi filled with opaque oil were sharply demonstrated. The morphologic types of bronchiectasis are classified as (1) cylindric, (2) ampullaceous, (3) saccular and (4) maniliform. The authors found that the acquired form occurred more frequently than did the congenital, and they postulate that chronic infections are the most important causes of the acquired forms. No favorite methods of therapy are especially advocated. Bronchoscopic examinations or treatments were apparently not often utilized. No enthusiasm is expressed for lobectomy. An extensive bibliography is appended.

Long Pulmonary Retention of Lipiodol

In the roentgen examination of the bronchial tract the use of lipiodol is common. Among the many hundreds of patients in which it has been employed, no reaction has been recorded. Wright (1) has reported one case in which there was retention of the opaque oil for a period of one year. At the time of instillation of the oil one of the main branches of the right bronchus was almost completely blocked. The oil passed beyond the obstruction into the lower branches, but was unable to pass toward the trachea. In this case death occurred and at autopsy no epithelial reaction was found. The following is quoted from the autopsy report: “When the lipio-dol is removed by a fat solvent and the section counterstained by eosin, the areas where the lipiodol occurred are seen to be made up of a lacework of finely reticulated cells with small round nuclei. The cytoplasm is extremely scanty, slightly vacuolated and extending in fine interconnecting strands from one cell to another. No collagen fibrils were demonstrated arising from these cells. The lipiodol appears to be inclosed in a form of cellular syncytium. The origin of these cells is probably the supporting tissue of the bronchus.” The following case, in which lipiodol has been retained for more than two years, without apparent obstruction, appears to be unique. W. L., white male, age 44, was referred for roentgen examination of the chest on Dec. 21, 1939. At this time, except for one calcified nodule in the right middle lobe his lungs were essentially clear. The left costophrenic angle did not open well, because of adhesions from a former pleurisy. Stereo films made in 1931, brought by the patient for comparison, showed similar findings. In April 1940, the patient entered a hospital for observation, and the use of lipiodol was advised to rule out the presence of bronchiectasis. The patient stated that he could not use iodine because of being allergic to the drug. After the administration of an opiate, however, lipiodol was instilled into the bronchi through a catheter placed in the trachea. No bronchiectasis was found and he was discharged from the hospital two days later. Two or three days after arriving home his hands became very edematous, and his eyes were swollen shut. He had chills, a high temperature, and rapid pulse, was very weak, and said that his stomach felt at times “as if it were dropping.” He called a physician, who sent him to another hospital. Here he was admitted with the following diagnoses: angioneurotic edema, with urticaria; moderately advanced chronic pulmonary tuberculosis, inactive; left pleural adhesions; chronic bronchitis secondary to tuberculosis. According to the patient's statement his temperature was 103 to 105° for a period of three weeks, during which time his weight dropped from 125 to 110 pounds. He remained in the hospital six weeks. In February 1942, the patient was referred for another chest examination.

CATHETERIZING THE SPHENOID

One is frequently called on to determine the presence or absence of infection in the sphenoid sinus. Because of its location, roentgen reports are often misleading. It therefore becomes imperative to attempt catheterization, either for irrigation or for the instillation of an opaque oil. For this reason a survey of 300 nonmacerated skulls was made to determine the percentage in which the sphenoid sinus could be catheterized, the reason for failure and some data that would make failure less common. It is self evident that if one could locate the ostium and have some way of knowing one has entered the sphenoid cavity irrigation would be easy. In a recent study of 1,600 macerated skulls, 1 it was found that the bony ostium is either round or oval, the diameter of the round bony ostium being 5.03 mm., while the oval ostium measures 4.02 mm. by 5.8 mm. The membranous ostium

A Simplified Method of Bronchography

SINCE the year 1921, when we succeeded for the first time in visualizing the bronchial tree of the human with lipiodol with no untoward result for the patient, bronchography has extended its field yearly. It has proved to be helpful in a number of pulmonary diseases in which changes in the bronchial tubes may exist, but, even after thirteen years we feel that the whole field of bronchography has not been covered, and that added information can be obtained from improved technics and better interpretations of roentgenograms. For several years we have used the transglottic method for the injection of opaque oil, injecting the oil by means of a long metallic catheter introduced directly into the trachea, after local anesthesia of the pharynx and larynx and under the control of the laryngeal mirror. One important feature in our technic has been the introduction of the intratracheal anesthesia previous to the injection of iodized oil. The principles which we established twelve years ago have been accepted almos...

Iodized Rapeseed Oil (Campiodol), an Improved Roentgenographic Opaque Oil

FOLLOWING the experimental introduction of campiodol (Frazier and Glaser, 1; Glaser, 2), it immediately became apparent that an iodized oil most efficient for the visualization of the various body cavities should have physical properties adaptable for each individual cavity. This led to the synthesis of dilution products as well as an emulsion. Undiluted campiodol is best used to outline the tracheobronchial tree. The dilution of campiodol with ethyl olive oil resulted in a free-flowing, less viscous compound, which still retained sufficient opacity for roentgenographic visualization. Equal parts of campiodol and ethyl olive oil were ideal for the visualization of the nasal sinuses; whereas a 4-to-1 dilution was invaluable for the outline of the subarachnoid space, the blood vessels, fistulæ, uterus, and salpinx. In order to visualize the genitourinary tract, an emulsion of campiodol proved the most satisfactory and has been utilized successfully in over 500 cases. The ability of certain oils to absorb iodine depends on the unsaturated property of some of the carbon atoms composing the glyceryl esters present in the oils. These unsaturated glyceryl fatty esters vary in their degrees of iodine absorption, and those with the highest amount of unsaturation will naturally absorb the largest amount of iodine. The iodine will be held in firm union once it has combined with the free valence linkage of the carbon atom. The iodization of rapeseed oil was accomplished by utilizing a variation of the methods of Hubl wherein mercuric chloride is used as a catalyst. This method of iodization has been described elsewhere (Raiziss, Glaser, and Clemence, 3). Rapeseed oil (colsa oil), which proved to be the most satisfactory for iodization purposes, is derived from the seeds of Brassica napus, Brassica campestris, Brassica rapa. It is a yellow, almost odorless oil with a specific gravity of 0.914 and an iodine value of 93.5 to 105.6. It is composed of the glycerides of stearic, erucic, and an oleic acid. Iodized rapeseed oil (campiodol) is a light yellowish, semi-viscous, transparent oil with a slightly aromatic odor and oleaginous taste. It contains from 43 to 45 per cent iodine and its specific gravity is from 1.2 to 1.3 at 20° centigrade. It is soluble in chloroform, ether, benzene, and carbon bisulphide, and insoluble in water and alcohol. This chemical compound deteriorates very slowly upon exposure to light and heat, some samples remaining stable for over a year, with which, upon radiographic exposure, an intense shadow is obtained. Campiodol (rapeseed oil) is an oil of very low toxicity. Given by mouth, dogs have withstood 6.75 c.c. per kilogram of body weight without toxic effects. Injected into the internal carotid artery, with ligation of the external carotid, the dogs were able to withstand 1.5 c.c. per kilogram of body weight.