Titers

The strength (concentration) of a titrant can also be expressed as its titer. The titer of a titrant is defined as the weight (in milligrams) of substance titrated that is consumed by 1 mL of the titrant. Thus it is specific to a particular substance titrated, meaning that it is expressed with respect to a specific substance titrated. For example, if the analyst is using an oxalic acid solution to titrate a solution of calcium oxide, the titer of the oxalic acid solution would be expressed as its CaO titer, or the weight of CaO that is consumed by 1 mL of the oxalic acid solution. Titer is typically used for repetitive routine work in which the same titrant is used repetitively to titrate a given analyte. 

What is the titer (expressed in milligrams per milliliter) of a solution of oxalic acid dihydrate with respect to calcium oxide if 21.49 mL of it was needed to titrate 0.2203 g of CaO  

The titer of the oxalic acid solution with respect to calcium oxide is calculated as follows  

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The efficiency of the filter is evaluated in terms of the titer reduction or log reduction value (LRV). The titer reduction is the ratio of the number of microorganisms in the input suspension to the number of organisms in the effluent. Similarly, the LRV is the log Q of this ratio. The ratio of the difference between the numbers of challenge microorganisms recovered upstream and downstream of the test filter to the average total challenge received by the filter... 

Mlcrofiltra.tlon, Various membrane filters have been used to remove viral agents from fluids. In some cases, membranes which have pores larger than the viral particle can be used if the filtration is conducted under conditions which allow for the adsorption of the viral particle to the membrane matrix. These are typically single-pass systems having pore sizes of 0.10—0.22 lm. Under situations which allow optimum adsorption, between 10—10 particles of poHovims (28—30 nm) were removed (34—36). The formation of a cake layer enhanced removal (35). The titer reduction when using 0.10—0.22 p.m membrane filters declined under conditions which minimized adsorption. By removal standards, these filters remove vimses at a rate on the low end of the desired titer reduction and the removal efficiency varies with differences in fluid chemistry and surface chemistry of viral agents (26). 

A PVDF membrane filter has been shown to remove >10 particles of vims for vimses >50 nm independent of fluid type (8). Vimses smaller than 50 nm are not removed as efficientiy but are removed in a predictable manner which correlates to the vims particle size. The chemistry of the suspending fluid affects titer reduction for vimses <50 nm owing to other removal mechanisms, such as adsorption, coming into play. The effects of these other mechanisms can be minimized by using filtration conditions that minimize adsorption. 

Size reference Filter Material Vims (size) Fluid Log titer reduction Reference... 

The complexity of the biochemical pathways, certainly for antibiotic synthesis, means that the careful and rigorous selection of the microorganism is the key to obtaining higher titers. However, most microorganisms only show thek tme potential when cultured under optimal fermentation conditions. Of... 

Phosphoms content usually is measured by a double end point titration method in which a 1.0-g sample is dissolved in a hot HNO —H2SO4—HCIO4 mixture. The pH is adjusted to 2.5 with NaOH, and the resulting H PO is titrated with 0.5-A[ NaOH, using an automatic titrator. The titer between the first and second end points is used to quantify the phosphoms as H PO. ... 

In nature, vitamin A aldehyde is produced by the oxidative cleavage of P-carotene by 15,15 - P-carotene dioxygenase. Alternatively, retinal is produced by oxidative cleavage of P-carotene to P-apo-S -carotenal followed by cleavage at the 15,15 -double bond to vitamin A aldehyde (47). Carotenoid biosynthesis and fermentation have been extensively studied both ia academic as well as ia iadustrial laboratories. On the commercial side, the focus of these iavestigations has been to iacrease fermentation titers by both classical and recombinant means. 

Although apparendy not commercially important, fermentation (qv) processes have been reported for the production of tocopherols. yispergillus niger (30), iMctohacter (31), Eugknagracilis Z. (32,33), and Mjcohacterium (34) have been shown to produce (RRR)-a-tocopherol. In the case of Eug/ena, titers of 140—180 mg/L have been reported. 

Prohibition, which made the sale of spirits illegal from 1920 to 1933, actually resulted in increased consumption from 530 to 750 million titers annually. At the end of Prohibition, many mergers occurred and modem technology was introduced to the industry. 

In England, the Magna Carta provided a standard of measurement for the sale of ale and wine. In 1643, the English Parliament proposed the first tax on distilled spirits. In the American colonies, William Kieft, Director General of New Nethedand, imposed the first liquor tax of two guilders on each half vat of beer in 1640. Alexander Hamilton initiated an excise tax on domestic spirits in 1791. The tax was resented and ultimately repealed in 1800 by Thomas Jefferson. Except during the War of 1812, domestic spirits remained untaxed until 1862. At that time, a tax of 0.02/L was implemented, which has been increased periodically. In January 1991, the Pederal Excise Tax on distilled spirits was raised to 3.56 per titer or 13.50 per proof gallon. In addition, many states have substantially increased the state excise taxes on distilled spirits. 

The principal impurities ia technical-grade bode acid are the by-product sulfates, <0.1 wt %, and vadous minor metallic impurities present in the borate ores. A bode acid titer is not an effective measure of purity because overdrying may result in partial conversion to metabotic acid and lead to B(0H)2 assays above 100%. High putity bode acid is prepared by recrystallization of technical-grade matedal. 

In addition to the toxic effects indicated for propranolol, acebutolol may produce hair loss and elevate antinuclear antibody titers (32). 

These neutralizing antibodies may arise because of a prior streptococcal infection, or prior streptokinase treatment (80—82). Titers of antibodies sufficient to neutralize a complete dose of 1.5 million units of streptokinase may be present even one year after enzyme treatment (83). 

In the development of new products, optimization of the fermentation medium for titer only often ignores the consequences of the medium properties on subsequent downstream processing steps such as filtration and chromatography. It is imperative, therefore, that there be effective communication and understanding between workers on the upstream and downstream phases of the produc t development if rational trade-offs are to be made to ensure overall optimahty of the process. One example is to make the conscious decision, in collaboration with those responsible for the downstream operations, whether to produce a protein in an unfolded form or in its native folded form the purification of the aggregated unfolded proteins is simpler than that of the native protein, but the refolding process itself to obtain the product in its final form may lack scalabihty. 

Mass, n. measure measurement dimension size gage titer proportion, extent, degree manner, -abweichimg,/. deviation from size, -analyse, /. volumetric analysis. 

Titer, n. titer, titre. -apparat, m. = Titrierap-parat. -fliissig eit, /. standard solution, titem, v.t. titrate. 

Z. 45 titers of ammonia contain the same, number of molecules as 2.45 titers of hydrogen, chloride. 

Universal anti-Rh sera deprived of anti-A or B-antibodies were prepared by contacting A and B-immunoadsorbents with human blood sera. To achieve zero titer in the Coombs agglutination test a portion of immunoadsorbent (80-160 mg) proportional to the initial serum titer (1 8-1 64, 1 ml) is required. The incorporation of A-immunoadsorbent into anti-B sera did not interfere with their titer and vice versa, Under the same circumstances an anti-Rh serum titer is lowered by one step or remains unchanged [125], Properties of this composite sorbent are therefore promising for its use in extracorporal hemisorption processes. 

Extracts from 152 plant species, representing 46 different families, were screened for effects on tobacco mosaic virus (TMV) replication in cucumber cotyledons. Twenty species have shown enough activity to warrant further study. Several members of the Caprifoliaceae family increased virus replication. An extract of Lonicera involucrata enlarged the virus lesions in local lesion hosts and produced a thirty fold increase in virus titer, but had no effect on virus replication in systemic hosts. The active material appears to affect the virus defense mechanism of local lesion hosts. An extract of common geranium is an active virus inhibitor. It inactivates TMV and TMV-RNA (ribonucleic acid) in vitro by forming non-infectious complexes. In vivo, it also inhibited starch lesion formation in cucumber cotyledons incited by TMV infection. 

Lesion formation represents a host response to virus infection. Factors preventing the formation of starch lesions incited by the virus do not necessarily mean that virus replication is inhibited at the same time. Therefore, the total virus titer in cotyledon samples treated with different concentrations of tannic acid was determined (Figure... 

The two highest concentrations of tannic acid (0.051 and 0.034%) resulted in a linear increase of virus titer up to 21 days after inoculation, even though the reduction of starch lesion formation was 91 and 64%, respectively. Thus, the virus must have replicated beyond the limitation of starch lesions. Further experiments indicated that a systemic spread of the virus into the primary leaves in cucumber plants could be obtained by daily brushing the noninoculated primary leaves (only the cotyledons were inoculated) with tannic acid following a vacuum infiltration of whole plants with 0.051% tannic acid 24 hours after virus inoculation. Primary leaves were shielded by tinfoil during the inoculation of the cotyledons to prevent accidental infection. Aerosol O.T. (0.1%) was incorporated in tannic... 

Figure 3. Virus titers of infected cucumber cotyledons infiltrated with different concentrations of tannic acid at various times after inoculation...

However, in a systemic host of TMV (P. floridana) the infiltration of tannic acid (0.034%) 24 hours after virus inoculation reduced virus titer about 75% during the first week after infection. After two weeks there was no significant difference in total virus content between tannic acid-treated and water-treated samples. Thus tannic acid does interfere with virus synthesis at an early stage in a temporary way. 

For the pathogenesis of multiple sklerosis, autoimmune T-lymphocy tes play a predominant role, which are directed against components of the neural myelin sheath. T-lymphocy tes by secreting cytokines such as interferon y maintain the chronic inflammation which destructs the myelin sheath. Also cytotoxic T-lymphocytes may participate directly. The cause of multiple sklerosis is unknown. Significantly increased antibody titers against several vitusses, mostly the measles virus, point to a (latent) virus infection initiating the disease. 

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