One-step Wash Research Articles

Dual-recognition colorimetric platform based on porous Au@Pt nanozymes for highly sensitive washing-free detection of Staphylococcus aureus.

Adual-recognition strategy is reportedto construct a one-step washing and highly efficient signal-transduction tag system for high-sensitivity colorimetric detection of Staphylococcus aureus (S. aureus). The porous (gold core)@(platinum shell) nanozymes (Au@PtNEs) as the signal labels show highly efficient peroxidase mimetic activity and arerobust. For the sake of simplicity the detection involved the use of a vancomycin-immobilized magnetic bead (MB) and aptamer-functionalized Au@PtNEs for dual-recognition detection in the presence of S. aureus.In addition, we designed a magnetic plate to fit the 96-well microplate to ensure consistent magnetic properties of each well, which can quickly remove unreacted Au@PtNEs and sample matrix while avoiding tedious washing steps. Subsequently, Au@PtNEs catalyze hydrogen peroxide (H2O2) to oxidize 3,3',5,5'-tetramethylbenzidine (TMB) generating a color signal. Finally, the developed Au@PtNEs-based dual-recognition washing-free colorimetric assay displayed a response in the range of S. aureus of 5 × 101-5 × 105 CFU/mL, and the detection limit was 40 CFU/mL within 1.5 h. In addition, S. aureus-fortified samples were analyzed to further evaluate the performance of the proposed method, which yielded average recoveries ranging from 93.66 to 112.44% and coefficients of variation (CVs) within the range 2.72-9.01%. These results furnish a novel horizon for the exploitation of a different mode of recognition and inexpensive enzyme-free assay platforms as an alternative to traditional enzyme-based immunoassays for the detection of other Gram-positive pathogenic bacteria.

COMPARATIVE EVALUATION OF THE DIMENSIONAL ACCURACY OF ONE-STEP VERSUS TWO STEP PUTTY WASH IMPRESSION TECHNIQUES USING TWO DIFFERENT COMMERCIALLY AVAILABLE ADDITION SILICONE ELASTOMERIC IMPRESSION MATERIALS – AN In-vitro STUDY

Introduction: An exact impression of dental and dentoalveolar structures is a significant and fundamental prerequisite for the exact fixture of the prosthesis. The advancement of the prosthesis with respect to fit, accuracy, and long life are dependent upon the impression materials, the strategies utilized, and the duration of time of pouring the impression.
 Aim: Compare and Evaluate the Dimensional Accuracy of One-Step versus Two-Step Putty Wash Impression Techniques Using Two Different Commercially Available Addition Silicone Elastomeric Impression Materials.
 Methodology: Impressions were made of a metal die having reference lines on it, by one-step wash impression technique and two-step impression technique. After making the impression, impression was allowed to set for 1 hour and then poured in Zhermack die stone. Die stone was allowed to set. Stone dies were obtained from each group. Metal die and stone dies from each group were assessed under stereo microscope 10x zoom using reference lines.
 Results: When compared to a one-step putty wash impression approach, a two-step putty wash impression process was more reliable. Comparing Virtual (Ivoclar Vivadent, USA) addition polyvinyl siloxane impression material to Aquasil (Dentsply, Germany), it was discovered that it was more accurate. Based on the findings, it has been determined that Ivoclar Vivadent Virtual addition silicone is more precise than Zhermack Aquasil addition silicone and that two-step putty wash impression method is more accurate than one-step putty wash impression method.
 Conclusion: Inside impediments of this study the following outcomes were drawn that two-stage clay wash impression method is more precise when contrasted with one stage clay wash impression strategy with a spacer of 1 mm for light body consistency expansion polyvinyl siloxane impression material. And The Ivoclar Vivadent Virtual expansion polyvinyl impression material showed more exactness when contrasted with Zhermack Aquasil expansion polyvinyl impression material utilizing one stage and two-stage clay wash impression strategies.

Simultaneous removal of toxic Pb(II) ions, poly(acrylic acid) and Triton X-100 from their mixed solution using engineered biochars obtained from horsetail herb precursor – Impact of post-activation treatment

The horsetail herb was used as the precursor and was subjected to direct physical activation with steam (800 °C for 1 h). Next two variants of post-activation treatment was applied: (1) two-steps washing procedure, firstly with a hot 10% solution of HCl and later with demineralized water (HBA_HCl sample) and (2) one-step washing procedure only with demineralized water (HBA_H2O sample). The final products were characterized towards its textural structure, acid-base properties and surface morphology. The obtained biochars were used as adsorbents for simultaneous removal of hazardous lead(II) ions, poly(acrylic acid) (PAA) polymer and Triton X-100 nonionic surfactant from their mixed solution.It was shown that Pb(II) and PAA adsorbed amounts (from the single and mixed systems of adsorbates) have the greatest values on the HBA_HCl surface in the double PAA + Pb(II) system (148.8 mg/g and 195.8 mg/g, respectively) and in the triple PAA + TRT + Pb(II) system (183.3 mg/g and 187.7 mg/g, respectively). The nonionic surfactant desorption reaches high level (83–100%), independently from using desorption agent (HNO3 or NaOH). Generally in the case of PAA, NaOH solution turned out to be more effective in adsorbent recovery process (especially from HBA_H2O surface), whereas in the case of Pb(II) ions desorption, HNO3 is more effective desorbing agent (74–96% desorption).

One-Step Cleaning-in-Place for Milking Systems and Mathematical Modeling for Deposit Removal from Stainless Steel Pipeline Using Blended Electrolyzed Oxidizing Water

Cleaning-in-place (CIP) is widely used on dairy farms to clean and sanitize the inner surfaces of milking system components after the milking event is completed. Recently, an increasing number of dairy farms are adopting a one-step CIP process, which combines the alkaline wash and acid wash cycles into one wash cycle. This one-step CIP has the advantage of reducing time, energy consumption, and chemical usage. Electrolyzed oxidizing (EO) water is an emerging technology that produces alkaline and acidic EO water by electrolyzing a dilute sodium chloride solution. Previous studies in our lab have shown that by blending the alkaline EO water with the acidic EO water at a certain ratio, the blended solution can be used as a one-step CIP alternative. Therefore, this study was undertaken to evaluate the deposit removal process during a one-step CIP wash cycle using the already optimized blended EO water solution and a stainless steel surface evaluation simulator. Stainless steel straight pipes were used as testing specimens, and the remaining milk deposit mass on the inner surfaces of the specimens was evaluated. A two-term exponential decay kinetic model was developed for the one-step blended EO water wash; the mathematical model comprises an initial fast deposit removal along with a slow deposit removal throughout the entire one-step wash. The proposed models were in agreement with the experimental data, with acceptable root mean square errors (0.08 mg mg-1 m-2) and low percentage error differences (5.16%). The relative light unit (RLU) reading from the adenosine triphosphate (ATP) bioluminescence method was also used as an indirect evaluation method at every time sampling point during the one-step wash cycle. Furthermore, scanning electron microscopy (SEM) was used to understand the residual deposit morphology on the specimen inner surfaces and qualitatively evaluate the cleanliness of the inner surfaces after the one-step wash. On average, 60% reduction of deposit coverage in the viewing area was observed after the blended EO water one-step wash as compared to after the warm water rinse cycle. Moreover, results showed that at the completion of the blended EO water one-step wash, the specimens could be considered clean, as indicated by the RLU cutoff reading for stainless steel material. Therefore, it is concluded that the developed and validated mathematical model for the blended EO water one-step wash could be used for CIP of the simulator.

Germination inhibition of Bacillus cereus spores: impact of the lipophilic character of inhibiting compounds

In this study, the impact of a range of organic acids and structurally similar alcohols with three to six carbon backbones and increasing lipophilic character, were tested on the germination behavior of B. cereus ATCC 14579 spores. This approach allowed substantiating whether the effectivity of the various compounds was largely dictated by membrane interference or a classic weak acid acidification effect. The octanol–water partition coefficient (log Poct/water) ranges from 0.25/0.33 to 2.03/1.96 for propanol/undissociated propionic acid and hexanol/undissociated hexanoic acid, respectively. Performance of germination assays at neutral (pH7) and acidic conditions (pH5.5) allowed for a comparative analysis of the action of dissociated versus undissociated acids, and the presumed pH-independent effect of the corresponding alcohols. Germination assays, based on both continuously measured optical density and time-based plating experiments, and microscopic observations demonstrated the correlation between the lipophilic character of the selected compounds and their inhibiting effect on spore germination. Real-time fluorescence based assays showed that membrane integrity in dormant spores was maintained in the presence of the tested inhibitors. Lowering the critical concentration of inhibitors by a one-step washing procedure resulted in the onset of nutrient-induced germination, indicating the reversible nature of the inhibition process. Furthermore, blocking of nutrient-induced germination in the presence of inhibitory concentrations of selected lipophilic acids and corresponding alcohols was by-passed upon addition of Ca-dipicolinic acid, pointing to loss of signaling capacity in germinant receptor-mediated germination activity. These findings show that lipophilicity is an important determinant for the ability of the selected acids and corresponding alcohols to accumulate in the spore inner membrane and their ability to act as a germination-inhibitor.

A new model for investigating in real-time the existence of Chemotaxis in human spermatozoa

To suggest a new approach to the research of chemotaxis between various media and human spermatozoa to solve the riddle of its existence. Laboratory experiments in which chemotaxis between human spermatozoa and follicular fluid (FF) as well as N-formyl was investigated. Male physiology laboratory and in vitro fertilization program unit. Follicular fluid was collected from 15 patients and used either fresh or after storage at -5 degrees C for less than 2 weeks. High-quality semen specimens were obtained from normal donors and underwent one-step washing with Ham's F-10 solution (Biological Industries, Kibbutz Beth Haemek, Israel). Assays were performed in real time by direct microscopical observation and quantitative determination of the disturbance in random movements of human spermatozoa caused by the tested media. Spermatozoa and tested media, including FF and N-formyl-Met-Leu-Phe were placed in a sealed minichamber and photographed with the aid of the multiple exposure photography technique. By analyzing photographed tracks of more than 80,000 moving spermatozoa, a physiologically insignificant deviation from randomness, corresponding to a 95% confidence interval of -0.57 +/- 0.46%, was found when spermatozoa swam along the concentration gradient of the tested media. The average velocity of spermatozoa swimming toward the test media was slightly lower (less than 5%) than that for spermatozoa swimming away, indicating, if anything, negative chemoattraction. Despite the high sensitivity of the model, neither natural FF nor synthetic N-formyl exerted any chemotaxis on human sperm. The advantages and potential use of this model for investigating chemotaxis by other biological and synthetic media are discussed.

A rapid spectrophotometric procedure for the simultaneous micro determination of carbamazepine and 5,5-diphenyl-hydantoin in blood

Carbamazepine and 5,5-diphenylhydantoin are simultaneously extracted from 100–200 μl blood with 1,2-dichloroethane. 5,5-Diphenylhydantoin is removed by a one-step wash into alkali. The dichloroethane is further washed with acid and then evaporated to dryness. 5,5-Diphenylhydantoin is determined in the alkali washing by a benzophenone procedure; carbamazepine is determined in the dried residue by the 9-methylacridine procedure earlier described. The combined method is rapid, reliable and has a detection threshold of less than 0.1 mg/100 ml for each drug.

Desalting Milk and Whey by Ion Retardation and Gel Filtration

Gel filtration on Sephadex G-10 and Bio-Gel P-2 and ion retardation on a Resin AG 11A8 were applied to desalting Cottage cheese whey.Gel filtration revealed difficulties when protein and lactose were collected. Lactose was not separated from calcium salts because of their similar elution volumes, and the whey was diluted to a large extent due to differences in elution volumes between protein and lactose fractions.More than 88% of calcium and 40% of ash were removed from 200ml of Cottage cheese whey with 100ml of the ion retardation resin. This desalting capacity was low compared to 450ml of the whey on a mixed bed of Dowex 1 and 50. However, the ion retardation is simpler, since a one-step washing of the resin with 0.1 n NaOH was sufficient to regenerate. Two hundred milliliters of skimmilk were desalted with 40% desalting and 45% decalcification on 100ml of the Resin AG 11A8. The mixed bed of ion exchangers did not desalt skimmilk because of coagulation of casein on the cation exchanger.