Borax as a Standard Buffer Solution

Abstract A buffer solution containing tris(hydroxymethyl)-aminomethane (0.01667 mol/kg) and its hydrochloride salt (0.0500 mol/kg) is proposed as a pH standard for the physiologically important pH range of 7.3 to 7.5. Standard pH values were assigned to this reference solution at temperatures from 0° to 50°C by means of measurements with hydrogen/silver chloride cells without transference. At 37°C, the assigned pH of this buffer solution is 7.382, with a temperature coefficient of -0.026 pH unit per degree Celsius. This new standard is more compatible with biologic fluids than is the previously certified phosphate buffer.

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Penyuluhan dan Pemeriksaan Leptospirosis terhadap Petani di Nagari Alahan Panjang Kabupaten Solok

Jurnal Warta Pengabdian Andalas ◽

10.25077/jwa.26.2.88-96.2019 ◽

2019 ◽

Vol 26 (2) ◽

pp. 88-96

Author(s):

Elizabeth Bahar ◽

Netti Suharti ◽

Roslaili Rasyid ◽

Andani Eka Putra ◽

Linosefa Linosefa ◽

...

Keyword(s):

Community Service ◽

Rapid Test ◽

Polluted Water ◽

Buffer Solution ◽

Stagnant Water ◽

Tropical Country ◽

Test Tool ◽

Standard Buffer Solution ◽

Power Point ◽

Positive Results

Leptospirosis is an infectious disease caused by Leptospira interogans (L interogans). The urine of rats is a carrier of L interrogans bacteria that pollutes stagnant water such as flooding both in rice fields and fields. Bacteria enter through the mucosa and sores or blisters when in contact with the polluted water. The mortality rate due to leptospirosis in Indonesia is reported to reach 2.5 - 16.45%, because it is a tropical country with quite high rainfall followed by flooding. Nagari Alahan Panjang Solok Regency is located at an altitude of 1400 - 1600 meters above sea level (masl) with rainfall of 2600 mm which is a vast agricultural area and the community is 90% farmers. Based on the problem above, the Department of Microbiology and Biology, Faculty of Medicine, Andalas University has held community service in Nagari Alahan Panjang, Solok Regency, for farmers, because farmers are at risk of being infected by Leptospira. The counseling method uses a power point slide and poster about leptospira followed by blood tests using the Standard Q rapid test for Leptospira IGM / IgG. About 48 farmers carried alcohol swabs at the tips of their fingers to take blood samples with fingersticks. As much as 10 ul of blood add 1 drop of standard buffer solution Q rapid test Leptospira IgM / IgG put in the rapid test tool well while stirring and wait 5 minutes. Positive results appear in the red line in the IgM / IgG area according to the control indicated on the rapid test tool. The conclusion that counseling can increase the knowledge of farmers to prevent leptospirosis with the discovery of 6.25% of farmers suspected of leptospirosis.

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Localization of acid phosphatases in root cap of rice plant

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100085423 ◽

1991 ◽

Vol 49 ◽

pp. 224-225

Author(s):

Y. R. Chen ◽

Y. F. Huang ◽

W. S. Chen

Keyword(s):

Rice Plant ◽

Developmental Stages ◽

Uranyl Acetate ◽

Root Cap ◽

Plant Tissues ◽

Acid Phosphatases ◽

Root Tips ◽

Buffer Solution ◽

Cacodylate Buffer ◽

Ethanol Series

Acid phosphatases are widely distributed in different tisssues of various plants. Studies on subcellular localization of acid phosphatases show they might be present in cell wall, plasma lemma, mitochondria, plastid, vacuole and nucleus. However, their localization in rice cell varies with developmental stages of cells and plant tissues. In present study, acid phosphatases occurring in root cap are examined.Sliced root tips of ten-day-old rice(Oryza sativa) seedlings were fixed in 0.1M cacodylate buffer containing 2.5% glutaraldehyde for 2h, washed overnight in same buffer solution, incubated in Gomori's solution at 37° C for 90min, post-fixed in OsO4, dehydrated in ethanol series and finally embeded in Spurr's resin. Sections were doubly stained with uranyl acetate and lead citrate, and observed under Hitachi H-600 at 75 KV.

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Determination of Radiochemical Purity and Pharmacokinetic Parameters of 99mTc-Sulphur Colloid and 99mTc-Tin Colloid

Nuklearmedizin ◽

10.1055/s-0037-1620659 ◽

1981 ◽

Vol 20 (06) ◽

pp. 279-282 ◽

Cited By ~ 2

Author(s):

D. Konstantinovska ◽

K. Milivojević ◽

J. Bzenić ◽

V. Jovanović

Keyword(s):

Radiochemical Purity ◽

Slow Component ◽

Pharmacokinetic Parameters ◽

Optimum Size ◽

Buffer Solution ◽

Chromatography Method ◽

Fast Phase ◽

Biodistribution Studies ◽

Biological Half Time

Labelling yield and radiochemical purity, higher than 95%, of 99mTc-colloid preparations were determined by using the paper chromatography method. Less than 3% of labelled citric acid, added to the preparation as a buffer solution, has been found in 99mTc-sulphur colloid. High radiochemical purity and optimum size of colloid particles has also been proved by biodistribution studies on experimental animals. The analysis performed has shown that more than 50% of 99mTc-colloid preparations excreted by urine is 99mTcO–, the remaining past 50% being protein bound 99mTc. Biological half-time of excretion of the fast phase is the same for both preparations, i.e. 10 min, while for the slow component it is 120 min in 99mTc-S-colloid and 160 min in 99mTc-Sn colloid.

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A microfluidic device with integrated impedance detection for λ-DNA

MRS Proceedings ◽

10.1557/proc-773-n6.5 ◽

2003 ◽

Vol 773 ◽

Cited By ~ 1

Author(s):

Myung-Il Park ◽

Jonging Hong ◽

Dae Sung Yoon ◽

Chong-Ook Park ◽

Geunbae Im

Keyword(s):

Microfluidic Device ◽

Electrochemical Impedance ◽

Direct Detection ◽

Full Potential ◽

Label Free ◽

Buffer Solution ◽

Detection Systems ◽

Significant Difference ◽

Detection Of Biomolecules ◽

Impedance Magnitude

AbstractThe large optical detection systems that are typically utilized at present may not be able to reach their full potential as portable analysis tools. Accurate, early, and fast diagnosis for many diseases requires the direct detection of biomolecules such as DNA, proteins, and cells. In this research, a glass microchip with integrated microelectrodes has been fabricated, and the performance of electrochemical impedance detection was investigated for the biomolecules. We have used label-free λ-DNA as a sample biomolecule. By changing the distance between microelectrodes, the significant difference between DW and the TE buffer solution is obtained from the impedance-frequency measurements. In addition, the comparison for the impedance magnitude of DW, the TE buffer, and λ-DNA at the same distance was analyzed.

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Grand-Reaction Method for Simulations of Ionization Equilibria and Ion Partitioning in a Broad Range of pH and Ionic Strength

10.26434/chemrxiv.9741746.v1 ◽

2019 ◽

Author(s):

Jonas Landsgesell ◽

Oleg Rud ◽

Pascal Hebbeker ◽

Raju Lunkad ◽

Peter Košovan ◽

...

Keyword(s):

Mean Field ◽

Coarse Grained ◽

Reactive System ◽

Acid Base ◽

Buffer Solution ◽

Reaction Method ◽

Ionization Equilibria ◽

Coarse Grained Simulations ◽

Ph Range ◽

Weak Polyelectrolytes

We introduce the grand-reaction method for coarse-grained simulations of acid-base equilibria in a system coupled to a reservoir at a given pH and concentration of added salt. It can be viewed as an extension of the constant-pH method and the reaction ensemble, combining explicit simulations of reactions within the system, and grand-canonical exchange of particles with the reservoir. Unlike the previously introduced methods, the grand-reaction method is applicable to acid-base equilibria in the whole pH range because it avoids known artifacts. However, the method is more general, and can be used for simulations of any reactive system coupled to a reservoir of a known composition. To demonstrate the advantages of the grand-reaction method, we simulated a model system: A solution of weak polyelectrolytes in equilibrium with a buffer solution. By carefully accounting for the exchange of all constituents, the method ensures that all chemical potentials are equal in the system and in the multi-component reservoir. Thus, the grand-reaction method is able to predict non-monotonic swelling of weak polyelectrolytes as a function of pH, that has been known from mean-field predictions and from experiments but has never been observed in coarse-grained simulations. Finally, we outline possible extensions and further generalizations of the method, and provide a set of guidelines to enable safe usage of the method by a broad community of users.<br><br>

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Detection of Hepatitis a Virus in Drinking Water by Enzyme -Immunoassay Using Ultracentrifugation for Virus Concentration

Water Science & Technology ◽

10.2166/wst.1985.0093 ◽

1985 ◽

Vol 17 (10) ◽

pp. 39-41 ◽

Cited By ~ 1

Author(s):

A. Schnattinger

Keyword(s):

Membrane Filtration ◽

Hepatitis A ◽

Hepatitis A Virus ◽

Solid Phase ◽

Phosphate Buffer Solution ◽

Enzyme Linked Immunosorbent Assay ◽

Virus Concentration ◽

Buffer Solution ◽

Solution Ph ◽

Two Stage

Ten litres of tapwater were seeded with 200 µl (8×108 HAV particles) of a commercial (Organon Teknika) suspension of hepatitis A virus. Following WALTER and RÜDIGER (1981), the contaminated tapwater was treated with a two-stage technique for concentration of viruses from solutions with low virus titers. The two-stage technique consists of aluminium hydroxideflocculation (200 mg/l Al2(SO4)3. 18 H2O, pH 5,4-5,6) as first stage, the second stage of a lysis of aluminium hydroxidegel with citric acid/sodium citrate-buffer (pH 4,7; 1 ml/l sample), separation of viruses from the lysate by ultracentrifugation and suspension in 1 ml phosphate buffer solution (pH 7,2). A commercial solid phase enzyme-linked immunosorbent assay (ELISA) was used for the detection of HAV. HAV was detecterl in the 10.000:1 concentrates, but not in the seeded 101 samples. Approximately 4×108 of the inoculated 8×108 HAV particles were found in the 1 ml concentrates. The efficiency of detection is about 50%, the virus concentration 5000-fold. Although the percentage loss of HAV in comparison with concentration by means of membrane filtration is similar, the ultracentrifugation method yields a larger sample/concentrate ratio, so that smaller amounts of HAV can be detected more efficiently because of the smaller end-volume.

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Improving Topical Skin Delivery of Monocrotaline Via Liposome Gel-based Nanosystems

Current Drug Delivery ◽

10.2174/1567201816666191029125300 ◽

2019 ◽

Vol 16 (10) ◽

pp. 940-950 ◽

Cited By ~ 1

Author(s):

Jiandong Yu ◽

Zhi Chen ◽

Yan-zhi Yin ◽

Chaoyuan Tang ◽

Enying Hu ◽

...

Keyword(s):

Gradient Method ◽

Encapsulation Efficiency ◽

Ph Value ◽

Topical Administration ◽

Ph Gradient ◽

Stability Factor ◽

Buffer Solution ◽

Skin Delivery ◽

Skin Retention

Background: In this study, a liposomal gel based on a pH-gradient method was used to increase the skin-layer retention of monocrotaline (MCT) for topical administration. Methods: Using the Box-Behnken design, different formulations were designed to form liposome suspensions with optimal encapsulation efficiency (EE%) and stability factor (KE). In order to keep MCT in liposomes and accumulate in skin slowly and selectively, MCT liposome suspensions were engineered into gels. Results: A pH-gradient method was used to prepare liposome suspensions. The optimal formulation of liposome suspensions (encapsulation efficiency: 83.10 ± 0.21%) was as follows: MCT 12 mg, soybean phosphatidyl choline (sbPC) 200 mg, cholesterol (CH) 41 mg, vitamin E (VE) 5 mg, and citric acid buffer solution (CBS) 4.0 10 mL (pH 7.0). The final formulation of liposomal gels consisted of 32 mL liposome suspensions, 4.76 mL deionized water, 0.40 g Carbopol-940, 1.6 g glycerol, 0.04 g methylparaben, and a suitable amount of triethanolamine for pH value adjustment. The results of in vitro drug release showed that MCT in liposomal gels could be released in 12 h constantly in physiological saline as a Ritger-Peppas model. Compared with plain MCT in gel form, liposomal MCT in gel had higher skin retention in vitro. Conclusion: In this study, liposomal gels were formed for greater skin retention of MCT. It is potentially beneficial for reducing toxicities of MCT by topical administration with liposomal gel.

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