Dipsticks

The molecular dipstick microscope is related to the AFM. It measures lubricant film thickness. The probe is lowered into the oil film on a surface (like the automobile engine crankcase dipstick). The tip is attracted to the surface by the surface tension of the film but repelled by van der Waal s forces from the hard substrate. By noting the height of the probe from the two surfaces as it makes contact, the film thickness can be measured with a precision of about 0.5 nm. 

A brass dipstick is recommended as a cheap and reliable means of determining the contents of a storage tank. A... 

In many cases it is inconvenient to use a dipstick, due to the position or location of the tank, and there are a variety of direct and remote contents gauges available, including gauge glasses, float and weight, float and swing arm, float and indicator, hydrostatic, electrical capacitance, etc. 

Most reservoirs have a capped opening for filling, an air vent, an oil level indicator or dipstick, a return line connection, a pump inlet or suction line connection, a drain line connection, and a drain plug (see Figure 40.19). 

E. S-Layers as Novel Matrix for Dipstick-Style Solid-Phase Immunoassays... 

Test strip and immunoflltration devices were developed by Ostermaier et al to detect sulfadiazine, sulfamethazine, and sulfamethoxypyridazine in milk. Direct competitive immunoassay was utilized with sulfonamide-horseradish peroxidase as the detector. The LOD for sulfamethazine for both the dipstick and immunoflltration was 10 pg kg for sulfadiazine, the LOD was 12 pg kg for the dipstick and 30 pg kg for immunoflltration. For sulfamethoxypyridazine, the LOD was 10 pgkg for the dipstick and 20 pgkg for immunoflltration. The devices were found to be suitable for on-site use with undiluted milk. 

The primary marker of structural kidney damage is proteinuria, even in patients with normal GFR. Clinically significant proteinuria is defined as urinary protein excretion greater than 300 mg/day or greater than 20 mcg/minute in a timed urine collection. Significant proteinuria can also be determined by a spot urine dipstick greater than 30 mg/dL or... 

Recent innovations for detecting malaria include DNA or RNA probes by polymerase chain reaction (PCR). These, however, are not widely available for clinical use. A rapid dipstick test (ParaSight F, Becton-Dickinson, Cockeyville, MD) reportedly has a sensitivity of 88% and a specificity of 97%, which is comparable to microscopy. However, ParaSight F can give false-positive results with rheumatoid factor thus microscopy remains the optimal test. 

The limitations of ELISA methods include the specificity of antibodies, the concentrations of primary antibody and antigen, and the type of reaction solution. Nonspecific binding of either of the antibodies to related antigens, unrelated proteins of other bacteria, or even the microtiter plate may lead to false positive reactions.49,52 57 Use of a monoclonal antibody may decrease crossreactivity with other antigens. For detection of low numbers of bacteria, as in drinking water, the sample may be filtered to concentrate the cells or cultured in a selective broth until it reaches the minimum detection limit for ELISA.49,58 Commercial test kits using dipsticks, immunoblots, and sandwich ELISA methods have been developed for the identification of pathogenic bacteria.58,59... 

Very practical for measurement between 4.2 K and room temperature are the so-called dipstick cryostats, designed for insertion into storage dewars (typically 5 cm neck diameter). Construction details of an insertable cryostat are reported in ref. [7],... 

In 1987, Uhlig [32] proposed and built a DR without a IK pot. This idea led to the commercial production of a dipstick DR which, thanks to its small diameter, can be immersed directly into the transport dewars, saving time and consumption of 4He in the transfer. More recently, the interest for the J-T DR has strongly increased because of the progress in the field of mechanical refrigerators which allowed the realization of a Dry DR (see Section 6.6). 

The nitrite test can be used to detect the presence of nitrate-reducing bacteria in the urine (such as E. coli). The leukocyte esterase test is a rapid dipstick test to detect pyuria. 

Construction of a dipstick type semiconductor detector system. 

Schneider E.Usleber E, Dietrich R, Maertlbauer E.Terplan G (1993) Rapid detection of chloramphenicol in raw milk by enzyme-linked immunofiltration and dipstick assay. In Haagsma N.Ruiter A (eds) Proceedings of the EuroResidues II conference Residues of veterinary drugs in food , vol 2. Veldhoven, p 627... 

Most clinical laboratories have established a standard battery of tests that includes most or all of the basic parameters listed in Table 20.12. If a dipstick is used to test the urine for several parameters, it is useful to use one that measures occult blood, even if a microscopic examination will count the number of red blood cells per high-power field. The means of obtaining the specimen should be indicated (i.e., normal voiding sample, clean catch, midstream, catheterization, suprapubic tap, or cytoscopy), especially in clinical trials in which an antidiuretic or antibiotic (or other relevant drug) is being tested. 

Genetic deficiency of fructokinase is benign and often detected incidentally when the urine is checked for glucose with a dipstick. Fructose 1-phosphate aldolase deficiency is a severe disease because of accumulation of fructose 1-phosphate in the liver and renal proximal tubules. Table 1-12-4 compares the two conditions. Symptoms are reversed after removing fructose and sucrose from the diet. 

ELISAs exist in many different formats, such as microwell assays (microtiter plates, strips), dipstick assays, and immunofiltration assays. 

The importance of brain circuitry is that it reminds us that these chemical neurotransmitters are not released willy-nilly throughout the brain. This is why the term chemical imbalance is so unsatisfactory. The brain is not a large water bottle into which these chemicals are poured and maintained in some precise balance. For that reason, there is no simple test to check a neurotransmitter level like the dipstick on your car s oil reservoir. Instead, your brain is a delicate instrument with predefined but ever-adapting pathways of communication. 

Drug/Lab test interactions Because false-positive readings were reported with the Ames N-Muitistix SG dipstick test for urinary protein when gabapentin was added to other antiepileptic drugs, the more specific sulfosalicylic acid precipitation procedure is recommended to determine the presence of urine protein. 

Youth with SUD require frequent visits with the treatment team, especially if they have comorbid psychiatric illness. During each visit, the clinician should monitor the patient s SUD and psychiatric symptoms, their social stressors, their compliance with medication and any adverse effects they may have experienced. Random urine dipstick testing for substances of abuse during the office visit, with tests such as the Roche On Trac system, may be a useful piece of the treatment plan provided that the adolescent is aware... 

A 59-year-old woman presents to an urgent care clinic with a 4-day history of frequent and painful urination. She has had fevers, chills, and flank pain for the last 2 days. Her physician advised her to immediately come to the clinic for evaluation. In the clinic she is febrile (38.5°C [101.3°F]) but otherwise stable and states she is not experiencing any nausea or vomiting. Her urine dipstick test is positive for leukocyte esterase. Urinalysis and urine culture are also ordered. Her past medical history is significant for three urinary tract infections in the past year. Each of these episodes was uncomplicated, treated with trimethoprim-sulfamethoxazole, and promptly resolved. She also has osteoporosis for which she takes a daily calcium supplement. The decision is made to treat her with oral antibiotics for a complicated urinary tract infection with close follow-up. Given her history what would be a reasonable empiric antibiotic choice Depending on the antibiotic choice are there potential drug interactions she should be counseled on ... 

Materials commonly use as solid supports include polystyrene, polyvinyl, nylon, glass, nitrocellulose, silica, polyacrylamide, or polystyrene beads. Separation of the bound from the free reagents can be achieved through either filtration for particulate solid supports such as agarose, polyacrylamide, and polystyrene beads, or centrifugation. For disposable forms of solid supports such as multiwell plates, plastic tubes, cuvettes, balls, and dipsticks, separation can be performed through simple rinsing steps. 

Common immunochemical assay formats to select from include the 96-well microtiter plates, dipsticks, coated test tubes, and membrane-based flow through devices. If the end-user is a trained technician working in a well-equipped laboratory and needs to detect and tentatively identify, for example, antimicrobial residues in hundreds of meat samples per day, a multiwell or other high-through-put format should be chosen. If, on the other hand, the end user is a quality control inspector at a milk factory who has limited time to find out whether the penicillin residues in the milk waiting to be unloaded exceed a certain level, the same reagents used in the first instance may require a more user-friendly format such as dipstick or membrane-based flow through device. 

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