Small Bath Research Articles

A heated stage and tissue culture chamber for electrophysiology.

A simple, inexpensive heating circuit is described for use with a warmed microscope stage, small tissue bath, and heated tissue culture chamber. A major consideration in the design of the apparatus is a compatability with electrophysiological studies. Thus, proper shielding and low profile for microelectrode positioning are featured.

Simplification of the water bath method for calibrating a RaBe neutron source

The water bath method for calibrating a RaBe neutron source was simplified by introducing a fitting function for the thermal neutron distribution in water. The simplified method requires only measurement of neutrons at a single position in a comparatively small water bath.

軟鋼のろう付強度におよぼす表面状態の影響

This investigation has been conducted to determine the impact strentgh of brazed (or soldered) joint of mild steel. To obtain some experimental data as to the effects of roughness of base metal, specimens of mild steel (SS41, 12×12×28 mm) were prepared according to the design of Fig. 1(a). The two abutt-ing surface of each specimens were identically finished by emery papers (No. 60, 120, 240, 400, 600), or other mechanical process such as milling, grinding, supper finishing and electrolytic polishing. These specimens were then brazed with BAG-8 filler metal using a resistance furnace (35 KW) operated in hydrogen atmosphere, or soldered by Pb-Sn alloy in the small resistance soldering bath (0.3 KW). Each specimens were machined according to the design of Fig. 1(b). The impact test of these specimens were carried out by 30 Kg-m charpy testing machine. The charpy test of these specimens gave the result shown as follows :(a) On the brazing by BAg-8(1) Impact strength of specimen polished by emery paper No. 120 was excellent, its value being 1.501 KG-m/cm2, and also that of one machined by milling cutter was very high. But impact strength of specimen polished by emery paper No. 600 was poor, its value being about 1.27 KG-m/cm2.(2) Impact strength of specimens with narrow joint clearance (t<0.1 mm) were very low, but that of one with wide joint clearance (t=0.4-0.55 mm) were very high.(3) All specimens were failured at filler metal zone as shown Photo. 4, 5.(b) On the soldering by Pb-Sn Alloy.(1) Impact strength of specimens polished by large grain size emery powder (No. 60, 120) showed about 0.3-0.35 Kg-m/cm2, but that of one polished by small grain size emery powder (No. 400, 600) were about 0.45-0.5 Kg-m/cm2.(2) Most of specimens were fractured at interface of joint, but a few of them were fractured at filler metal zone as shown Photo. 7.

Noradrenaline release from isolated muscles of the nictitating membrane of the cat.

1. When the splanchnic nerves were stimulated in the cat for periods of up to 2 hr, the amount of adrenaline taken up by the nictitating membrane was very small; the highest figure was 0.37 mug/g, corrected for losses.2. The noradrenaline (NA) stores of the isolated medial muscle of the nictitating membrane were labelled with [(3)H]NA, and field stimulation of single muscles was carried out in a small organ bath. A stimulation period of 5 min with supramaximal shocks delivered at a frequency of 25/sec produced a mean release of NA into the bath fluid of 0.46 +/- 0.13 mug/g (uncorrected). Phenoxybenzamine, 10 mug/ml., increased this figure by a factor of 2-3.6. When corrections were made for the amount of transmitter metabolized before it could be collected, 47% of the tissue content of NA were shown to be released during the 5 min stimulation of the normal membrane, and about 55% in the presence of phenoxybenzamine. Prolonged stimulation of a phenoxybenzamine-treated membrane was apt to lead to loss of tissue stores of NA.3. Calculation of the degree of labelling of the NA in the tissue, and of NA released by stimulation, indicated that about 21% of endogenous NA had been replaced by labelled compound both in the tissue and in the overflow.4. Transmitter release per pulse was estimated by applying 720-1330 shocks at frequencies of 4 or 6/sec to membranes exposed to phenoxybenzamine. Mean release of NA per shock and per g tissue was 1.3 ng (corrected for losses). This represents 3.5 x 10(-4) of the tissue content determined at the end of the experiment.

Effect of protracted ultrasonic irradiation on the growth of seedlings of Vicia faba.

ULTRASOUND is being used increasingly in medicine—both for diagnostic techniques and for therapy—and in industrial processes1,2. The nature and extent of the biological effects of such radiations are, however, still uncertain. Certainly at high intensity damage results from a rise in temperature in the organism, but it seems likely that other, non-thermal effects may occur. Breakdown of DNA in solution has been observed3, and the streaming of fluids which has been demonstrated within cells may produce damage4. Lethal effects in Daphnae have also been reported5 in conditions where the possibility of any fatal temperature rise could be excluded. This preliminary communication reports an effect of irradiation in a small ultrasonic cleaning bath on the growth of the main tap root in Vicia faba seedlings.

Transparent Conductive Beakers for Temperature Control of Small Processing Baths.

Transparent Conductive Beakers for Temperature Control of Small Processing Baths.

A small fluidized-solid constant temperature bath

This note describes the construction and operation of a small constant temperature bath in which a fluidized solid is the heat-transfer medium.

A Small Thermostatic Bath Controlled by Thermoelectric System

A Small Thermostatic Bath Controlled by Thermoelectric System

The Physics of Blood Flow in Capillaries: I. The Nature of the Motion

In many capillaries erythrocytes travel singly, separated by segments of plasma (bolus flow). The peculiar flow pattern, within the plasma, has been studied visually in a model in which air bubbles separated by short columns of liquid flow through a glass tube. Injection of dye reveals an "eddy-like" motion, in that each fluid element repeatedly describes a closed circuit. The possible significance of this "mixing motion" in relation to gaseous equilibration (e.g., in pulmonary capillaries) has been studied in a thermal analogue. A copper tube passed first through a constant temperature bath which brought the fluid to a uniform temperature T(1), and then through a second smaller bath at a lower temperature T(2). From the final temperature T(3) of the fluid, which was collected in a thermally insulated flask, a calculation of the heat transfer was made (i.e., from the flow and the temperature drop (T(1)-T(3))). Bolus flow was up to twice as effective in transferring heat as Poiseuille flow (no bubbles in fluid). The theory of modelling was employed in order to apply this thermal data to gaseous equilibration, especially in pulmonary capillaries. It was concluded that gaseous equilibration may be considerably accelerated by bolus flow, though this may be more of a limiting factor in peripheral capillaries than in the pulmonary circulation. The result supports the assumption of complete mixing in plasma made by Roughton and Forster in 1957.

Semi-automatic control system for producing constant cooling rates

This control system was designed and is best suited for cooling, at a constant rate, the metal sample block of a differential thermal analysis apparatus used for studying supercooling, melting and solidification phenomena in organic materials. An automatically-controlled flow of liquid refrigerant, passing through a simple heat exchanger, is used to cool the primary liquid circulating continuously in the coil system of the block. The apparatus is also suitable for uniform cooling of a small water or oil bath. For either application, controlled cooling rates of up to about 2° C/min are attainable. Using refrigerated water, control is possible from 95 down to about 10° C depending on the rate, but the range could be extended to lower temperatures by the choice of suitable liquid coolants.

The Patient in the Respirator

MR. S., AGED THIRTY-TWO, came to us after an attack of poliomyelitis which left the greater part of his body paralyzed. He has been in a respirator for nine months. We have learned much from our experience with him which might have value for other nurses who will be required to give nursing care to patients of this type. Baths may be given by placing a small bath basin inside the machine, usually between the patient's legs, one nurse working from either side. In this case, however, since the loss of pressure due to. four portholes being opened at once is too great a strain upon the patient, a more suitable method has been devised. The bath basin is filled with very warm water and placed on the bedside table which is drawn close to the respirator. The bath towel is placed inside the machine and left there throughout the bath. The rather small washcloth must be squeezed quite dry, to prevent the water dripping out as it is taken through the porthole. One half of the anterior surface of the body is bathed before the nurse proceeds to the other side, and there is a rest interval between the two halves of the bath. The back may be washed and rubbed with the aid of an orderly who draws the patient toward him as the nurse works from the opposite side. The nurse works very swiftly when four portholes are open. Small draw sheets, which fit across the mattress of the respirator without too much surplus to tuck in, have been made in the sewing room. These are changed every day or oftener if necessary. The large sheet is changed only every other day. Six people are needed to do this as quickly and efficiently as possible, since the patient is taken out of the respirator during this procedure. The nurse should have everything in readiness before the respirator is opened. All pillows and sandbags used for support should be removed through the bedpan porthole so that there will be no danger of their slipping out to block the runner when the carriage is being returned. A large sheet folded in half lengthwise fits the respirator mattress very well as the lower sheet. The upper end is folded in small pleats for approximately twentyfour inches, while the lower end is rolled up to meet the folds at the top. The clean draw sheet and small rubber sheet are folded together ready for use after the bottom sheet is changed. Three orderlies are needed to lift the patient, and two nurses to change the sheet. As soon as the carrier comes out, the nurses on one side of the patient and the orderlies on the other side loosen and remove the bottom sheet. The clean sheet is started at the top. Special care is taken to get it tucked in smoothly under the neck and shoulders. This is done by

A Device for Orienting and Embedding Minute Objects

A device is described for embedding objects 200μ or less in paraffin in accurate orientation. It consists of a small paraffin bath heated by a removable coil of wire, and having a water jacket for rapid cooling of the block. Orientation is effected under the microscope using electrically heated needles.

On a new method of detecting pyro-electricity

Introduction—pyro-electricity has been investigated by various methods. Sir David Brewster heated his crystals and brought them into contact with small, very light, insulating particles: If these adhered, the presence of pyro-electricity in the crystal was inferred. He also used a very delicately suspended brass needle. Being a conductor it was attracted to a charged crystal when this was brought near to it. Hankel placed the crystal under investigation in a small bath of copper or iron filings, which was then put into a hotair oven. The filings did not entirely cover the whole crystal, but one corner, edge, or face, whichever was required, was left exposed. A very small platinum sphere connected to an electrometer was then brought near to the exposed portion. The charge induced on the sphere was taken as a measure of the charge developed at the particular spot on the crystal opposite the platinum sphere.

PHYSICAL EQUIPMENT OF THERAPEUTIC POOLS

The development in recent years of hydrogymnastic technic and methods has brought to the fore possibilities for this rather unique combination of physical therapeutic modalities heretofore but slightly realized. The treatment of various types of illness in pools originated probably centuries ago, for we read in the Bible of the sick being thus treated. It has also long been known that paralytic patients could move with less effort in the water because of its buoyancy. Many physicians have used small tanks and bath tubs for a number of years for this purpose. During the past four years at the Orthopaedic Hospital in Los Angeles we have been using a large, shallow pool for many types of conditions—flaccid and spastic paralysis, joint and postsurgical conditions and, most notably, the disabilities resulting from poliomyelitis. Other types of orthopedic cases, however, are just as satisfactorily treated under water. The chief values of pool

Butterflies and Hybernation

SOME time late in last autumn, a tortoiseshell butterfly took refuge in a small bath room in this house, established itself on, the ceiling, and there remained, immovable, throughout the winter. On the 10th of this month it shifted its position, and on the 12th flew out of the open window. On the 19th, and again to-day, I have seen a tortoiseshell butterfly fluttering about the garden, and should not be surprised if this early rover were the same individual as that which has undoubtedly wintered here. Half a dozen gauzy-winged green flies also hybernated in close company with the butterfly, but they woke up and flew a fortnight or so before the tortoiseshell butterfly stirred.