Average Recovery Rate Research Articles

Characteristics and electrochemical membrane sensors for selective study and determination of some antidepressant drugs in their pharmaceutical preparations

The construction and electrochemical characterisation of potentiometric sensors of the PVC-membrane type are described being developed for the determination of selected antidepressants; namely: Olanzapine, Oxazepam, and Lorazepam. The sensing PVC-membranes incorporate the ion-associates of the drug cations with ammonium reineckate as selective materials dispersed in 2-nitrophenyl-octylether (NPOE) or dibutyl sebacate (DBS) as the plasticizers of choice. These ISEs exhibit rapid, stable and nearly Nernstian response over a relatively wide concentration range of 1 ´ 10-7 M – 0.01 mol L-1 for Olanzapine and 1 ´ 10-6 – 0.01 mol L-1 for Oxazepam and Lorazepam, in mild acidic solutions with pH 4.5. No interferences caused by either inorganic or organic species were found. The three electrodes developed have been tested for potentiometric titrations of all three drugs, as well as for their direct determination via the respective calibration curves. The individual experiments then resulted in average recovery rates in an interval of 98.4-99.2 %, with the R.S.D. of ca. ±1.5 % (n = 3) for all three analytes of interest. Finally, the method proposed has been applied to the determination of the three drugs in pharmaceutical formulations and in urine, when the results obtained were comparable to those obtained with the reference HPLC measurements.

Changes in activity impairment and work productivity after treatment for vitreous hemorrhage due to proliferative diabetic retinopathy: Secondary outcomes from a randomized controlled trial (DRCR Retina Network Protocol AB).

Vitreous hemorrhage from proliferative diabetic retinopathy can cause severe vision loss. DRCR Retina Network Protocol AB was a randomized clinical trial comparing intravitreal aflibercept versus vitrectomy with panretinal photocoagulation and found no difference in the average rate of visual recovery over 104 weeks. Herein, we describe patient-reported outcome measures from Protocol AB. Secondary analysis of a multicenter (39 sites) randomized clinical trial. The Work Productivity and Activity Impairment Questionnaire was administered at 4, 12, 24, 36, 52, 68, 84, and 104 weeks. Main outcomes were mean change in activity impairment and work productivity loss over 24 and 104 weeks (area under the curve). Mean (SD) activity impairment at baseline was 58% (27%) in the aflibercept group (N = 99) and 56% (30%) in the vitrectomy group (N = 105). The mean reduction in activity impairment from baseline over 24 weeks was 21% (25%) in the aflibercept group and 27% (31%) in the vitrectomy group (adjusted difference = -6.8% [95% CI, -12.7% to -0.9%], P = .02); over 104 weeks, the adjusted mean difference was -3.1% (95% CI, -9.2% to 3.0%, P = .31). Mean work productivity loss at baseline was 51% (28%) in the aflibercept group (N = 44) and 58% (30%) in the vitrectomy group (N = 43). The mean reduction in work productivity loss from baseline over 24 weeks (area under the curve) was 19% (23%) in the aflibercept group and 31% (24%) in the vitrectomy group (adjusted difference = -8.3% [95% CI, -16.8% to 0.2%], P = .06); over 104 weeks, the adjusted mean difference was -9.1% (95% CI, -18.4% to 0.2%, P = .05). Participants with vitreous hemorrhage from proliferative diabetic retinopathy had less activity impairment over 24 weeks when treated initially with vitrectomy and panretinal photocoagulation versus intravitreal aflibercept. The trend was similar for work productivity but not statistically significant. By 104 weeks, the improvements were similar in the two treatment groups. ClinicalTrials.gov NCT02858076.

Degumming and characterization of Bombyx mori and non-mulberry silks from Saturniidae silkworms

In this study, cocoons and degummed silk samples of Bombyx mori and twenty Saturniidae species of the genera Actias, Attacus, Argema, Antheraea, Caligula, Callosamia, Cricula, Epiphora, Hyalophora, Loepa, Samia and Saturnia are studied to gain an insight into their morphology, chemical composition and physical structure. For this purpose, silk samples are characterized by optical microscopy and FTIR spectroscopy in attenuated total reflection mode (ATR-FTIR spectroscopy). Furthermore, degummed silk samples are analyzed for their amino acid (AA) composition by GC-FID. In the course of method development, various degumming methods are tested using alkalis, citric acid, enzymes and detergents. A mixture of 0.1% sodium carbonate and 2.5% ethylenediamine proves to be an effective agent for degumming Saturniidae and B. mori cocoons. After hydrolysis of the fibroin filaments with 6 N hydrochloric acid and derivatization with propyl chloroformate, fifteen AAs are identified and qualified. This method shows a satisfactory overall analytical performance with an average recovery rate of 95% at the medium concentration level. The chemical composition of the different silks was considered comparatively. Within a genus, the analyses usually show a high degree of similarity in AA composition and the resulting structural indices, whereas differences are found between genera.

Optimization and application of determination method of cholesterol in various dishes

To establish a rapid and accurate method for the determination of cholesterol in a variety of finished dishes. The samples were saponified with ethanol and potassium hydroxide solution at 80 ℃ for 0.5 h, then vortexed and mixed fully with ultrapure water, and extracted twice with 25 mL n-hexane. The extracting solution were evaporated to dryness under vacuum and redissolved by ethanol, finally determined by gas chromatograph. The sample loading solution was separated by HP-5 capillary column(30 m×0.25 mm, 0.25 μm) and quantified with external standard method. The method had good linearity in the concentration range of 2.5-250 μg/mL for cholesterol and the correlation coefficient was 0.9999. The detection limit was 0.25 mg/100 g edible part, and the limit of quantification was 0.75 mg/100 g edible part. Three representative samples were picked for spiked recovery experiments with three concentration levels according to their content of cholesterol. The average recovery rates ranged from 91.1% to 101%, and the relative standard deviations were not more than 5%. The content range of cholesterol in 15 vegan dishes was from negative to 10.3 mg/100 g edible part, in 14 dishes contained meat and vegetable was from 2.34 to 80.2 mg/100 g edible part and in 9 pure meat dishes was from 25.4 to 288 mg/100 g edible part. Compared with the national standard method, the method is simple to operate and more friendly to the experimenter while ensuring the accuracy and sensitivity requirements. It can meet the needs of efficient batch determination of cholesterol in a variety of finished dishes.

Quantifying Airborne Spray Drift Using String Collectors

Efficient collection of airborne spray is crucial to reduce environmental contamination and ensure effective pesticide application in agriculture. This study explored the efficacy of passive spray drift samplers, focusing on string collectors for capturing airborne spray droplets. String collectors were assessed in laboratory experiments using a spray drift tunnel. A notable average recovery rate of 82% was observed when string collectors were examined immediately after pesticide capture. Collection efficiency was found to increase with wind speed. Of all the string collectors, string #5, a yarn type, demonstrated consistent collection efficiency, meeting the criteria for passive samplers. This includes effective droplet capture at low wind speeds, a high recovery rate of 93.31%, and suitability for field experiments. Field evaluations further underlined the efficiency of string #5, showcasing its ability to capture spray drift across a wider area and varied heights with less effort and manpower compared to traditional nylon screens.

Simultaneous Determination of 12 Preservatives in Pastries Using Gas Chromatography-Mass Spectrometry.

(1) Background: Preservatives may pose a potential threat to human health. To ensure food safety, this study has devised a method that concurrently detects a dozen preservatives (acetic acid, propionic acid, dehydroacetic acid, benzoic acid, sorbic acid, dimethyl fumarate, methyl parahydroxybenzoate, ethyl parahydroxybenzoate, propyl parahydroxybenzoate, isopropyl parahydroxybenzoate, butyl parahydroxybenzoate, and isobutyl parahydroxybenzoate) in pastry, utilizing gas chromatography-mass spectrometry. (2) Methods: The pastry samples were acidified with hydrochloric acid, extracted with acetonitrile via vortexing, purified by hexane and saturated with sodium chloride solution to remove lipids and impurities, and then concentrated via nitrogen blowing. The method was then quantitatively analyzed using GC-MS with the internal standard method after methanol re-dissolution. (3) Results: The results showed that the content of the 12 preservatives had good linearity within the range of 1.0-50 μg/mL, with correlation coefficients all greater than 0.99. The method detection limit was 0.04-2.00 mg/kg and the quantification limit was 0.12-6.67 mg/kg. The average recovery rates of the samples at three different spiked concentrations of low, medium, and high were 70.18-109.22%, and the relative standard deviations were 1.82-9.79% (n = 6). (4) Conclusions: This method requires a small amount of sample, has high sensitivity, and is simple and fast to operate, making it suitable for the simultaneous determination of 12 preservatives in pastry. This approach contributes to the effective surveillance and regulation of preservative usage in pastries, thereby safeguarding public well-being.

Digital-twin-controlled ventilation for real-time resilience against transmission of airborne infectious disease in an indoor food court

During a disruption, actionable insights generated from real-time data of the disrupted system can be used to dynamically recalibrate mitigation and recovery responses but there is currently a paucity of investigation on such assessment and management of resilience in real time. In this study, we propose the concept of real-time resilience to encapsulate the capacity of a disrupted system to continuously recalibrate its responses and minimize its damage. Quantitative metrics to assess the real-time resilience are also established. Subsequently, a digital-twin-based control for mechanical ventilation systems was developed as a tool to enable real-time resilience against airborne infection in indoor spaces. For demonstration, numerical simulations were performed with the adoption of the new tool in an indoor food court. Results showed that the gross resilience of the diners was enhanced in terms of improvements to the metrics of disruption duration (26%–61%), loss of resilience (2%–39%), and average rate of recovery (26%–74%). At the same time, the tempo-spatial variations suggested that increasing the ventilation rate increased the dilution and dispersion of infectious aerosols simultaneously, which can have opposing effects on individual resilience depending on the diner’s location. The trade-off between real-time resilience and energy use was discussed based on the results. Practical applications: This study proposed a new tool based on the concept of real-time resilience to control ventilation to mitigate the indoor transmission of airborne infectious disease. The tool utilized numerical simulations to assess the tempo-spatial variation of infection risks and determine the adaptive changes needed for risk mitigation based on the predictive assessment. The evaluation of the tool using the proposed metrics of real-time resilience was demonstrated and the results showed that adoption of the tool can lead to improvements in disruption duration, loss of resilience, and average rate of recovery for diners in a food court.

Research on a Magnetic Separation-Based Rapid Nucleic Acid Extraction System and Its Detection Applications.

Nucleic acid extraction represents the "first step" in molecular diagnostic experiments. The quality of this extraction serves as a fundamental prerequisite for ensuring the accuracy of nucleic acid detection. This article presents a comprehensive design scheme for a rapid automated nucleic acid extraction system based on magnetic separation. The design and implementation of the system are analyzed and investigated in-depth, focusing on the core methods, hardware control, and software control of the automated nucleic acid extraction system. Additionally, a study and evaluation were carried out concerning the nucleic acid extraction and detection aspects encompassed by the system. The results demonstrate that the temperature deviation in the lysis and elution fluids is approximately ±1 °C, the positioning accuracy of the system's movement is ±0.005 mm, the average magnetic bead recovery rate is 94.98%, and the average nucleic acid recovery rate is 91.83%. The developed automated system and manual methods are employed for sample extraction, enabling the isolation of highly pure nucleic acids from bacteria, blood, and animal tissues for RT-PCR detection. The instrument employs lysis temperatures ranging from 70-80 °C, elution temperature of 80 °C, and drying time of 5-10 min, with a total extraction time of less than 35 min for different sample types. Overall, the system yields high nucleic acid concentration and purity, exhibits stable instrument operation, good repeatability, high efficiency, and low cost. It meets the requirements of genetic-level research and is worthy of clinical promotion and usage.

Core-Shell-Shell Upconversion Nanomaterials Applying for Simultaneous Immunofluorescent Detection of Fenpropathrin and Procymidone.

This study synthesized the NaGdF4@NaGdF4: Yb, Tm@NaGdF4: Yb, Nd upconversion nanoparticles (UCNPs), combined with another three-layer structure NaYF4@NaYF4: Yb, Er@NaYF4 UCNPs, with a core-shell-shell structure, effectively suppressing fluorescence quenching and significantly improving upconversion luminescence efficiency. Two types of modified UCNPs were coupled with antibodies against fenpropathrin and procymidone to form signal probes, and magnetic nanoparticles were coupled with antigens of fenpropathrin and procymidone to form capture probes. A rapid and sensitive fluorescence immunoassay for the simultaneous detection of fenpropathrin and procymidone was established based on the principle of specific binding of antigen and antibody and magnetic separation technology. Under the optimal competitive reaction conditions, different concentrations of fenpropathrin and procymidone standards were added to collect the capture probe-signal probe complex. The fluorescence values at 542 nm and 802 nm were measured using 980 nm excitation luminescence. The results showed that the detection limits of fenpropathrin and procymidone were 0.114 µg/kg and 0.082 µg/kg, respectively, with sensitivities of 8.15 µg/kg and 7.98 µg/kg, and they were applied to the detection of fenpropathrin and procymidone in tomatoes, cucumbers, and cabbage. The average recovery rates were 86.5~100.2% and 85.61~102.43%, respectively, with coefficients of variation less than 10%. The results showed good consistency with the detection results of high-performance liquid chromatography, proving that this method has good accuracy and is suitable for the rapid detection of fenpropathrin and procymidone in food.

Development of integrated smartphone/resistive biosensor for on-site rapid environmental monitoring of organophosphate pesticides in food and water

Organophosphate (OP) pesticides remain a worldwide health concern due to their acute or chronic poisoning and widespread use in agriculture around the world. There is a need for robust and field-deployable tools for onsite detection of OP pesticides in food and water. Herein, we present an integrated smartphone/resistive biosensor for simple, rapid, reagentless, and sensitive monitoring of OP pesticides in food and environmental water. The biosensor leverages the hydrolytic activity of acetylcholinesterase (AChE) to its substrate, acetylcholine (ACh), and unique transport properties of polyaniline nanofibers (PAnNFs) of chitosan/AChE/PAnNF/carbon nanotube (CNT) nanocomposite film on a gold interdigitated electrode. The principle of the sensor relies on OP inhibiting AChE, thus, reducing the rate of ACh hydrolysis and consequently decreasing the rate of protons doping the PAnNFs. Such resulted decrease in conductance of PAnNF can be used to quantify OP pesticides in a sample. A mobile app for the biosensor was developed for analyzing measurement data and displaying and sharing testing results. Under optimal conditions, the biosensor demonstrated a wide linear range (1 ppt–100 ppb) with a low detection limit (0.304 ppt) and high reproducibility (RSD <5%) for Paraoxon-Methyl (PM), a model analyte. Furthermore, the biosensor was successfully applied for analyzing PM spiked food/water samples with an average recovery rate of 98.3% and provided comparable results with liquid chromatography-mass spectrometry. As such, the nanosensing platform provides a promising tool for onsite rapid and sensitive detection of OP pesticides in food and environmental water.

Analytical Ultracentrifugation-Calibrated Anion-Exchange Chromatography for Sensitive and Intact Determination of Osteopontin in Infant Formula and Dairy Products.

Osteopontin is a crucial protein ingredient that has been applied in fortified dairy products and infant formula. It has great significance to infant gut health and brain development. However, current techniques including enzyme-linked immunosorbent assay and liquid chromatography coupled with mass spectrometry are still facing the bottleneck of low sensitivity and indirect quantification. Moreover, the unavailable certified commercial OPN standard hinders its accurate quantification. Herein, a novel method of anion-exchange chromatography was established to determine OPN concentration in several dairy matrices. The polarity-reversed capillary isoelectric focusing was utilized to measure the exact isoelectric point (pI) to support method development for OPN separation. Analytical ultracentrifugation was used to calibrate the purity of intact OPN to develop an in-house reference standard. The method showed the merits of limits of detection to 0.04 mg/100 g, relative standard deviation of reproducibility <5% for 13 out of 14 tested matrices, and an average recovery rate of 101.3%. This method has shown the potential to be adopted as an international standard method for the quantification of intact OPN in infant formula and dairy products.

Residual behavior and dietary risk assessment of albendazole as fungicide in citrus orchards.

Albendazole is a broad-spectrum fungicide that shows great potential in controlling fungal diseases in citrus. To quantify the dissipation behavior, residue distribution, and dietary risk of albendazole in citrus, we developed an UPLC-MS/MS analysis protocol. The average recovery rate of albendazole in whole citrus and citrus pulp ranged from 74 to 105% with an RSD of 3 to 8%, and a limit of quantification of 0.01mgkg-1. The degradation half-lives were 2.8-3.0 and 5.7-17.0days in whole citrus and citrus pulp, respectively, and the final residues of albendazole were <0.059mgkg-1 with a risk quotient of <1. This study not only demonstrates that the dietary risk of albendazole in citrus is negligible, but also provides empirical data to establish the maximum residual limit (MRL) for the safe application of albendazole in citrus orchards to meet the requirements for food safety as well as international trade.

High Value Conversion Technology of Nickel in Waste Electrolytes of Nitrogen Trifluoride by Electrolysis

The method of precipitation treatment of high-nickel waste electrolytic slag was studied, coupled with multi-step treatment to improve the recovery rate of nickel. In this study, HNO3 was used as dissolving agent, NaOH and Na2CO3 as precipitating agents, and the waste electrolytic slag was dissolved in the liquid phase and then precipitated. The results show that the electroslag with high nickel content can be completely dissolved under the optimal solid-liquid ratio of 1:10. When the pH of the leaching solution was adjusted to 7.5 by 5% NaOH solution, the iron removal rate could reach 99.3%. When the pH was adjusted to 11 with 5% Na2CO3, the nickel could be completely precipitated after standing, and the main component was basic nickel carbonate. The further recovery experiments show that high purity NiO can be obtained after the basic nickel carbonate is oxidized and calcined, and the average recovery rate of nickel is 92.4%. This study is of great practical significance to improve the treatment efficiency of the chemical precipitation method, reduce the operating cost of the chemical precipitation method, and reduce the production of secondary pollutants in the process of nickel recycling.

Formulation of Ethanolic Extract of Guava Fruit Flesh (Psidium guajava L.) as a Lip Moisturizer

Background: Guava fruit (Psidium guajava L.) is known for its antioxidant properties, attributed to its content of beta carotene and phenolic compounds such as quercetin, guavin, protocatechuic acid, ferulic acid, gallic acid, caffeic acid, and vitamin C. However, the use of guava fruit flesh in lip balm formulations has not been extensively studied. Objective: This research aims to determine whether the ethanolic extract of guava fruit flesh can be formulated into a lip balm preparation that provides moisture at certain concentrations without irritating the lip skin. Method: This study utilized the guava fruit flesh (Psidium guajava L.) as the test material. Phytochemical analysis and lip balm formulations were prepared at concentrations of 2.5%, 5%, 7.5%, 10%, along with a blank control. Commercially available products were used as a comparison. The physical quality evaluation of the formulations included tests for homogeneity, pH, melting point, stability, preference, and effectiveness on the lip skin using a moisture checker device. Results: the ethanolic extract of guava fruit flesh (Psidium guajava L.) can be formulated into a lip balm. The pH of the lip balm formulations ranged from 6.0 to 6.2 immediately after preparation and from 5.8 to 6.1 after 12 weeks of storage. The melting point of the formulations was between 58-62°C. The lip balm with a concentration of 7.5% was the most preferred in the preference test. The formulations remained stable in terms of odor, color, and shape over a 12-week storage period. The lip balm with a 10% concentration provided the best moisturizing effect on the lips, achieving a 23.1% improvement, while the commercial comparison product had an average recovery rate of 26.1%, falling under the "moist" category. Conclusion: the ethanolic extract lip balm formulations did not cause any irritation to the skin and potential used as moisturizer

Establishment of a sensitive UPLC-MS/MS method to quantify safinamide in rat plasma.

A fast, simple, and sensitive ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established for the quantification of safinamide in rat plasma. Plasma samples were treated with acetonitrile for protein precipitation, and diazepam was used as an internal standard (IS). The analytes were separated on an Acquity UPLC C18 (2.1mm × 50mm, 1.7μm) chromatographic column with gradient elution using a mobile phase (0.1% formic acid-acetonitrile). Then, the eluates were detected by electrospray ionization (ESI) in positive ion mode. The analytes were quantified by multiple reaction monitoring (MRM) using the transition m/z 303.3→215.0 of safinamide and m/z 285.0→154.0 of IS. Safinamide had good linearity in the concentration range of 1.0-2000ng/mL, and the lower limit of quantitation (LLOQ) was 1.0ng/mL. The intra- and inter-day precision and accuracy of safinamide were less than 7.63%, while the average recovery rate was 92.98%-100.29%. The method was validated to be stable and had low noise, short chromatographic run time, wide linear range, small sample volumes, low sample injection volumes, and high sensitivity. Therefore, it can be used in pharmacokinetics and preclinical and clinical studies.

Fluorometric investigation of boric acid-pyridoxal 5′ phosphate interaction: A turn-on-fluorescence assay for the detection of boric acid in water bodies and fetal bovine serum

Boron is a trace element that is beneficial to plants as well as human and animal health. Boron supplementation is beneficial for absorbing vitamin D and magnesium, activating antioxidant enzymes and anticancer treatments. However, environmental accumulation of boron exceeding the permissible limit harms plants, animals and humans. Boric acid (BA), a form of boron, is known to interact with biomolecules such as NAD+/NADH, vitamin C, vitamin D, vitamin B1 and vitamin B6 determined through techniques like NMR, mass spectrometry, and FTIR. The fluorescence interaction of BA with the biologically active form of vitamin B6, Pyridoxal 5′ phosphate (PLP), has not been explored to date. Therefore, this study reports the interaction mechanism of BA with PLP via fluorescence spectroscopy analysis. The absorption, excitation and fluorescence lifetime measurements indicate that BA may form a complex through the mono or di-esterification of the phenolic hydroxyl group and aldehyde of PLP at different pH, forming the boronate esters. BA addition enhanced the fluorescence intensity of PLP by 12–22-fold in phosphate buffer (at acidic, neutral, and basic pH conditions). On the other hand, in citrate buffer at pH 4.0, BA enhanced PLP fluorescence by 28-fold. The binding constant for BA in phosphate buffer and citrate buffer was found to be 173 mol−1·L and 623 mol−1·L, respectively. At the same time, the detection limit for BA was found to be 445 μg/L and 212 μg/L in respective buffers. Therefore, PLP was used as a turn-on fluorescent probe to detect and quantify BA in water bodies and fetal bovine serum (FBS). The developed method successfully detected BA in environmental water bodies, achieving an average recovery rate of 99.84% (with a relative standard deviation (RSD) of 0.38%) in phosphate buffer and 81.59% (RSD, 4.56%) in citrate buffer. Furthermore, detecting BA in PLP-spiked FBS has been demonstrated in citrate buffer at pH 4.0, yielding an average recovery rate of 108.25% (RSD, 3.19%). Therefore, this study provides a basis for understanding the interaction of biomolecules like vitamins with boronates which aid in development of novel boronate based therapeutics and also helps in understanding the metabolic reactions of vitamin derivatives using fluorescence spectroscopy.

Development and validation of a stability indicating green analytical method for the simultaneous estimation of l-glutathione, n-acetyl l-cysteine and Vitamin C in marketed formulation using UV–visible spectroscopy

BackgroundAn efficient ultraviolet spectrophotometric method has been devised for the simultaneous analysis of l-glutathione, n-acetyl l-cysteine and Vitamin C in combined tablet dosage forms. This method is characterized by its simplicity, rapidity, precision, accuracy and cost-effectiveness. It employs the simultaneous equation method to determine the concentrations of l-glutathione, n-acetyl l-cysteine and Vitamin C.ResultsThe concentration range of 50–250 μg/mL for l-glutathione, 15–75 μg/mL for n-acetyl l-cysteine and 2–10 μg/mL for Vitamin C demonstrated linearity in this study. The simultaneous equation method was employed to determine the drug concentrations. The average recovery rates were found to be 99.94 ± 0.61% for l-glutathione, 100.90 ± 0.96 for n-acetyl l-cysteine and 99.81 ± 0.58% for Vitamin C. Stability studies were performed under various stress conditions.ConclusionThe method employed in this study was observed to possess qualities of simplicity, accuracy and precision, making it suitable for the simultaneous determination of l-glutathione, n-acetyl l-cysteine and Vitamin C in pharmaceutical tablet dosage forms. The analysis results were statistically validated and supported by recovery studies and stability studies, further enhancing the credibility of the method.

Clogging characteristics and recovery effects of porous asphalt concrete with different gradations

ABSTRACT Permeable pavement is easy to be blocked, which significantly affects the functions of drainage and skid resistance. Relevant researches lack void clogging and cleaning for PAC with different air voids and nominal maximum particle sizes. This paper designed seven kinds of PAC specimens to study PAC's clogging characteristics and cleaning methods. Specifically, the permeability coefficient decay of PAC caused by clogging was tested. Then, a novel test called fluorescence tracing method was proposed to evaluate the clogging depth and area. Afterward, high-pressure washing, vacuum cleaning, and the combination of high-pressure washing and vacuum cleaning (H&V) were used to study void recovery characteristics. Results showed that the critical clogging particle size of PAC-13 with 16% air voids and PAC-10 with 20% air voids were 0.15-0.3 mm; the critical clogging particle size of PAC-13 with 18% air voids was 0.3-0.6 mm; the critical clogging particle size of PAC-13 and PAC-16 with air voids of 20%, 22%, 24% were 0.6-1.18 mm. Furthermore, the clogging depths of PAC-13 didn't exceed 28 mm, and the proportions of the clogging area didn’t exceed 37%. The average recovery rates of vacuum cleaning and H&V were more than 70%, obviously better than that of high-pressure washing.

Application of intergenic sequence between ND5 and ND6 as novel target for authentication and quantification of Oviductus Ranae

Oviductus Ranae (OR), dried oviducts from Rana dybowskii (RD), is a valuable food and medicine included by Chinese pharmacopeia, mainly produced in Changbai Mountain area of China. Economically motivated adulteration with oviducts from unclear species has become one of the most concerned food safety issues. Existing methods based on DNA sequencing are cost and time consuming, making them unfit for rapid authentication and quantification. Here, we developed a PCR/RT-PCR method targeting a RD specific intergenic sequence region termed IGS56 in mtDNA (Genbank NC_023528.1, 17059–17154 bp). Common primers in RD close species (F1-ND5/R1-ND6), RD specific primers (F2-IGS56/R2-ND6) and universal primers (F0–18 s/R0–18 s) were used for authentication by PCR, while RD specific primers (F3-IGS56-RT/R3-ND6-RT) and reference primers (F0–18 s-RT/R0–18 s-RT) were used for quantification by RT-PCR. For authentication, standard OR sample together with 19 batches OR samples obtained from different sites of Changbai mountain area were all identified to be RD. For RT-PCR based quantification, calibration curve with a good linear correlation (R2 =0.9915), was plotted with Ct ratio (Specificity Ct /Reference Ct) and OR percentage mixed by oviducts of R.nigromaculata. The accuracy of RT-PCR method established was verified to be high, with an average recovery rate of 106.744%.

Should higher education be subsidized more?

SUMMARY We investigate in which countries fiscal externalities provide a justification for increasing subsidies to higher education. First, we show that the marginal fiscal recovery rate, i.e., the ratio of the change in total net fiscal revenues and the change in total subsidy costs caused by a small change in tuition subsidies, is the key statistic: if larger than a well-specified threshold value, then a small increase in subsidies is desirable from a welfare point of view. We also show that the marginal fiscal recovery rate depends on three statistics: the elasticity of participation with respect to subsidies, the success probability of the marginal student, and the ratio of the net fiscal revenue gain and the subsidy level of a degree in higher education. Second, we use this formula to approximate the marginal fiscal recovery rate in twenty OECD countries. The average marginal fiscal recovery rate is equal to 0.94, meaning that, on average, 0.94 euro is recovered of an increase in subsidies by one euro. This average hides substantial heterogeneity between countries. In six countries, the marginal fiscal recovery rate is larger than one, implying that an increase in subsidies to higher education is unambiguously desirable (i.e., a Pareto improvement) in these countries. In the other 14 countries, the marginal fiscal recovery rate is below one. Yet, if the degree of inequality aversion is not extreme, then increasing subsidies is also desirable in 12 additional countries. Third, to check the quality of our approximation of the marginal fiscal recovery rate, we simulate it for Belgium (region of Flanders) on the basis of a more detailed model. This simulation provides a somewhat lower, yet fairly similar result compared to the approximation.