Simulating Spatiotemporal Dynamics of Sichuan Grassland Net Primary Productivity Using the CASA Model and In Situ Observations

Net primary productivity (NPP) is an important indicator for grassland resource management and sustainable development. In this paper, the NPP of Sichuan grasslands was estimated by the Carnegie-Ames-Stanford Approach (CASA) model. The results were validated with in situ data. The overall precision reached 70%; alpine meadow had the highest precision at greater than 75%, among the three types of grasslands validated. The spatial and temporal variations of Sichuan grasslands were analyzed. The absorbed photosynthetic active radiation (APAR), light use efficiency (ε), and NPP of Sichuan grasslands peaked in August, which was a vigorous growth period during 2011. High values of APAR existed in the southwest regions in altitudes from 2000 m to 4000 m. Light use efficiency (ε) varied in the different types of grasslands. The Sichuan grassland NPP was mainly distributed in the region of 3000–5000 m altitude. The NPP of alpine meadow accounted for 50% of the total NPP of Sichuan grasslands

The Assessment on Synergistic Activity of Ebselen and Silver Ion Against Yersinia pseudotuberculosis

Yersinia pseudotuberculosis is a foodborne zoonotic bacterium that is pathogenic to guinea pigs, rabbits, and mice. It also causes pseudotuberculosis in humans. However, it still lacked the scientific basis for control. Here, we found out that Ebselen (EbSe) exhibited synergistic antibacterial activity with silver nitrate (Ag+) against Y. pseudotuberculosis YpIII strain with high efficacy in vitro using UV-visible light absorption spectrum, 5,5’-dithiobis-(2-nitrobenzoic acid), laser scanning confocal microscope, flow cytometry, transmission electron microscopy and Western blotting assays. The depletion of total glutathione (GSH) amount and inhibition of thioredoxin reductase (TrxR) activity in thiol-dependent redox system revealed the destructiveness of EbSe-Ag+-caused intracellular oxidative stress. Furthermore, a YpIII-caused mice gastroenteritis model was constructed. EbSe-Ag+ significantly reduced bacterial loads with low toxicity. It also down-regulated the expression levels of interferon (IL)-1β and tumor necrosis factor-α, up-regulated the expression level of IL-10 on-site. All the in vivo results demonstrated the antibacterial activity and immune-modulatory property of EbSe-Ag+. Collectively, these results provided academic fundament for further analysis and development of EbSe-Ag+ as the antibacterial agents for pseudotuberculosis control

Optimization of Measurement Condition for Determination of Tritium in Air by Liquid Scintillation Counting

During the operation of the reactor, a large amount of tritium is released into the surrounding air through the waste gas treatment system and the plant ventilation system. Tritium is very easy to replace hydrogen in water molecules, and can enter the human body through breathing, resulting in internal radiation hazards. Therefore, it is necessary to study the measurement of tritium in ambient air. At present, there is no national or industrial standard for the measurement of tritium in air. In this paper, the liquid scintillation counter was used to measure the activity concentration of tritium in air. It is found that the detection limit of the activity concentration of tritium in the air mainly depends on ambient temperature, relative humidity, sample amount, detection efficiency of the instrument, background count rate of the instrument, measurement time, etc. Among them, ambient temperature and relative humidity are inherent characteristics of air samples. Therefore, in order to reduce the detection limit and shorten the measurement time as much as possible, three aspects must be considered which is reducing the background count rate, improving the detection efficiency and increasing the sample volume. Possible approaches include selecting background water and scintillation fluid with the lowest possible counts, selecting the appropriate counting area, and optimizing the mixing ratio of sample and scintillation fluid. In order to reduce the effect of water and scintillation fluid on the background, 11 different sources of background water and 3 types of scintillation fluid were selected for testing. The samples were prepared according to the ratio of 8 mL of water to 12 mL of scintillation fluid, and the long-term counting measurement was carried out after being stored in the dark for 24 h. The measurement results show that the count rate range of the background water sample varies from 2.373 min-1 to 3.441 min-1, and the difference between the maximum value and the minimum value is 1.068 min-1, which also shows that the selection of the background water sample is very critical. For three scintillation fluids including Gold Star Quanta, OtpiPhase HiSafe 3 and UItima Gold LLT, there is no significant difference in background and detection efficiency.In order to further reduce the detection limit, a figure of merit (FOM) was introduced, which is the ratio of the square of the detection efficiency of the radionuclide of interest to the background count rate. To maximize FOM, it is necessary to reduce the sample background count rate while maintaining a high detection efficiency, which can be achieved by optimizing the count area. By changing the lower threshold (LL) and upper threshold (UL) of the pulse height discriminator, a series of counted regions and the corresponding FOM can be obtained. The optimal count interval is 0.35-4.35 keV, which maximizes FOM. For full spectrum counting, the sample detection efficiency is 29.27% and the background counting rate is 6.53 min-1, from which the FOM is calculated to be 131.2. After optimizing the counting area, although the detection efficiency is only 25.62%, the background is only 2.42 min-1, and the FOM reaches 271.2. The optimization of the counting interval reduces the detection efficiency from 29.27% to 25.62%, a decrease of 12.47%. But there is an even bigger reduction in background, at 170%. In terms of optimizing the combination of water and scintillation fluid, samples were prepared and measured with water contents of 35%, 40%, 45%, 50%, and 55%, respectively. The comparison results show that when the water content is 40% and 45%, the quality factor of the measurement system reaches the maximum, and the detection limit reaches the minimum. Tritium in air was measured under optimized conditions. The detection limit of typical samples is 20 mBq/m3, and the measurement time is 16 h, which is 1/2 shorter than that of full spectrum counting

The safety and efficacy of tolvaptan in the treatment of patients with autosomal dominant polycystic kidney disease: A systematic review and meta-analysis

Background: The irreversible progression of autosomal dominant polycystic kidney disease (ADPKD) to end-stage renal disease (ESRD) is delayed by tolvaptan. Therefore, we aim to systematically estimate and evaluate the efficacy and safety of tolvaptan in the treatment of ADPKD. Methods: Two reviewers independently searched all published randomized controlled trials studies in PubMed, EMBASE, Web of Science and Cochrane databases, extracted data, assessed bias risk and rated the quality of evidence. Data were analyzed by the RevMan software. Results: We identified 8 trials including 2135 patients. Both of the decline of estimated glomerular filtration rate (eGFR) [MD = 1.89, 95% CI (0.74, 3.04), P = 0.001] and total kidney volume (TKV) [MD = −3.32, 95% CI (−4.57, −2.07), P < 0.001] were delayed in tolvaptan group compared with placebo group in ADPKD patients. The use of tolvaptan delayed TKV progression in the different-month subgroups [MD = −69.99, 95% CI (−91.05, −48.94), P < 0.001]. Tolvaptan reduced renal pain [RR = 0.66, 95% CI (0.54, 0.81), P < 0.001] and hematuria events [RR = 0.55, 95% CI (0.41, 0.74), P < 0.001] in ADPKD patients. However, the prevalence of thirst [RR = 2.75, 95% CI (2.34, 3.24), P < 0.001] and nocturia events [RR = 3.01, 95% CI (1.27, 7.11), P = 0.01] were increased in tolvaptan group. There is no significant difference of hypertension events [RR = 0.92, 95% CI (0.82, 1.03), P = 0.13] in tolvaptan group compared placebo group. Conclusions: This meta-analysis suggests that tolvaptan may improve clinical progression in patients with ADPKD without significantly increasing the risk of adverse reactions. Resumen: Antecedentes: La progresión irreversible de la enfermedad renal poliquística autosómica dominante (ERPAD) a enfermedad renal en etapa final (ESRD) es demorada por tolvaptan. Por tanto, nuestro objetivo fue estimar y calcular sistemáticamente la eficacia y seguridad de tolvaptan en el tratamiento de ERPAD. Métodos: Dos revisores buscaron de manera independiente todos los estudios publicados sobre ensayos controlados aleatorizados en las bases de datos de PubMed, Embase, Web of Science y Cochrane, extrayendo datos, evaluando el riesgo de sesgo y calificando la calidad de la evidencia. Los datos fueron analizados utilizando el software RevMan. Resultados: Identificamos ocho ensayos, que incluyeron 2.135 pacientes. Tanto la reducción de la tasa de filtración glomerular estimada (eGFR) [MD = 1,89, IC 95% (0,74, 3,04), p = 0,001] como el volumen renal total (VRT) [MD = −3,32, IC 95% (−4,57, −2,07), p < 0,001] se demoraron en el grupo tolvaptan, en comparación con el grupo placebo en los pacientes con ERPAD. El uso de tolvaptan demoró la progresión del VRT en los subgrupos de diferentes meses [MD = −69,99, IC 95% (−91,05, −48,94), p < 0,001]. Tolvaptan redujo el dolor renal [RR = 0,66, IC 95% (0,54, 0,81), p < 0,001] y los episodios de hematuria [RR = 0,55, IC 95% (0,41, 0,74), p < 0,001] en los pacientes con ERPAD. Sin embargo, la prevalencia de episodios de sed [RR = 2,75, IC 95% (2,34, 3,24), p < 0,001] y nocturia [RR = 3,01, IC 95% (1,27, 7,11), p = 0,01] se incrementó en el grupo tolvaptan. No existe diferencia significativa en cuanto a episodios de hipertensión [RR = 0,92, IC 95% (0,82, 1,03), p = 0,13] en el grupo tolvaptan, en comparación con el grupo placebo. Conclusiones: Este metaanálisis sugiere que tolvaptan puede mejorar la progresión clínica en los pacientes con ERPAD, sin incrementar significativamente el riesgo de reacciones adversas

Turn-on fluorescent detection of cyanide based on the inner filter effect of silver nanoparticles

A simple, sensitive fluorescent method for detecting cyanide has been developed based on the inner filter effect (IFE) of silver nanoparticles (Ag NPs). With a high extinction coefficient and tunable plasmon absorption feature, Ag NPs are expected to be a powerful absorber to tune the emission of the fluorophore in the IFE-based fluorescent assays. In the present work, we developed a turn-on fluorescent assay for cyanide based on the strong absorption of Ag NPs to both excitation and emission light of an isolated fluorescence indicator. In the presence of cyanide, the absorber Ag NPs will dissolve gradually, which then leads to recovery of the IFE-decreased emission of the fluorophore. The concentration of Ag NPs in the detection system was found to affect the fluorescence response toward cyanide greatly. Under the optimum conditions, the present IFE-based approach can detect cyanide ranging from 5.0 Â 10 À7 to 6.0 Â 10 À4 M with a detection limit of 2.5 Â 10 À7 M, which is much lower than the corresponding absorbance-based approach and compares favorably with other reported fluorescent methods. In addition, the present method possesses a good selectivity for cyanide over other common anions and further application in cyanide-spiked water samples suggested a recovery between 98.2 and 101.4%. Therefore, our proposed IFE-based fluorescent method is expected to be applied for cyanide determination in practical applications

Activated E2F activity induces cell death in papillary thyroid carcinoma K1 cells with enhanced Wnt signaling.

Disruption of Wnt signaling often happens in tumorigenesis, but whether Wnt signaling affects the early stages of thyroid tumor, such as papillary thyroid carcinoma, is still a question, especially in the papillary thyroid carcinoma without genomic RET/PTC mutation. In this study, we demonstrated the important function of Wnt signaling in papillary thyroid carcinoma K1 cells, which have no RET/PTC mutation. We found that K1 cells have enhanced Wnt signaling in comparison to normal thyroid cells. We further demonstrated that K1 cells require the enhanced Wnt signaling for growth and survival. Interestingly, we identified that enhancing E2F activity by either knockdown of Rb or overexpression of Cyclin D1 induces cell death in K1 cells. And we further revealed that the cell death is caused by enhanced oxidative stress. Our studies present a novel cell model to support the key roles of Wnt signaling in early stage of thyroid tumor, and also provide an alternative way to limit thyroid cancer

The Assessment on Synergistic Activity of Ebselen and Silver Ion Against Yersinia pseudotuberculosis

Yersinia pseudotuberculosis is a foodborne zoonotic bacterium that is pathogenic to guinea pigs, rabbits, and mice. It also causes pseudotuberculosis in humans. However, it still lacked the scientific basis for control. Here, we found out that Ebselen (EbSe) exhibited synergistic antibacterial activity with silver nitrate (Ag+) against Y. pseudotuberculosis YpIII strain with high efficacy in vitro using UV-visible light absorption spectrum, 5,5’-dithiobis-(2-nitrobenzoic acid), laser scanning confocal microscope, flow cytometry, transmission electron microscopy and Western blotting assays. The depletion of total glutathione (GSH) amount and inhibition of thioredoxin reductase (TrxR) activity in thiol-dependent redox system revealed the destructiveness of EbSe-Ag+-caused intracellular oxidative stress. Furthermore, a YpIII-caused mice gastroenteritis model was constructed. EbSe-Ag+ significantly reduced bacterial loads with low toxicity. It also down-regulated the expression levels of interferon (IL)-1β and tumor necrosis factor-α, up-regulated the expression level of IL-10 on-site. All the in vivo results demonstrated the antibacterial activity and immune-modulatory property of EbSe-Ag+. Collectively, these results provided academic fundament for further analysis and development of EbSe-Ag+ as the antibacterial agents for pseudotuberculosis control

Enhanced E2F activity induced cell death in K1 cells.

<p>(A) Immuno blot showed decreased Rb level in cells with knockdown of Rb. Actin serves as a loading control; (B) E2F activity reporter showed knockdown of Rb increased E2F activity; (C) Cell growth was measured in Nthy-ori 3–1 and K1 cells with knockdown of Rb; (D) Cell death was measured in K1 cells with knockdown of Rb by Annexin V and PI assay; (E) Immuno blot showed overexpression of Cyclin D1 and increased level of phosphor-Rb. Rb and Actin serves as loading controls; (F) E2F activity reporter showed overexpression of Cyclin D1 increased E2F activity; (G) and (H) Cell growth was measured in Nthy-ori 3–1 (G) and K1 cells (H) with overexpression of Cyclin D1; (I) Cell death was measured in K1 cells with overexpression of Cyclin D1 by Annexin V and PI assay on Day 4. *<0.05, **<0.01.</p

K1 cells depend on Wnt signaling for growth and survival.

<p>(A) Immuno blot showed overexpression of DN-TCF4. Actin serves as a loading control; (B) TOP-Flash reporter showed overexpression of DN-TCF4 inhibited the Wnt signaling. FOP-Flash served as a control; (C) and (D) Cell growth was measured in Nthy-ori 3–1 (C) and K1 cells (D) with overexpression of DN-TCF4; (E) Cell death was measured in K1 cells with overexpression of DN-TCF4 by Annexin V and PI assay; (F) Immuno blot showed overexpression of TCF4. Actin serves as a loading control; (G) TOP-Flash reporter showed overexpression of TCF4 enhanced the Wnt signaling. FOP-Flash served as a control; (H) and (I) Cell growth was measured in Nthy-ori 3–1 (H) and K1 cells (I) with overexpression of TCF4. **<0.01.</p

K1 cells have enhanced Wnt signaling.

<p>(A) Wnt signaling activity reporter TOP-Flash reporter showed K1 cells have higher Wnt signaling activity than normal thyroid Nthy-ori 3–1 cells. FOP-Flash served as a control; (B) Immuno blot showed increased β-catenin level and decreased E-cadherin level in whole cell extraction from K1 cells. Actin serves as a loading control; (C) Quantification of band intensity in (B); (D) Immuno blot showed decreased β-catenin level and E-cadherin level in membrane extraction from K1 cells. Na,K-ATPase serves as a loading control; (E) Quantification of band intensity in (D) (F) Immuno blot showed increased β-catenin level in both nuclear and cytoplasmic extraction from K1 cells. Actin and Histone H3 serves as loading controls; (G) Quantification of band intensity in (F); (H) mRNA expression of c-Myc and Cyclin D1 relative to the level of GAPDH in Nthy-ori 3–1 and K1 cells. The data were collected from at least three independent experiments. **<0.01.</p