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Cryopreservation of Citrus madurensis zygotic embryonic axes by vitrification: importance of pregrowth and preculture conditions

Cho EG, Hor YL, Kim HH, Rao VR, Engelmann F

Cryo Letters, 2001 Nov-Dec;22(6):391-6.
PMID: 11788881

The role of pregrowth and preculture treatments in terms of both medium composition and exposure duration on survival of embryonic axes of Citrus madurensis after cryopreservation using the vitrification procedure was investigated. The optimal pregrowth treatment for excised embryonic axes was a 3-day treatment with 0.1M sucrose. Preculture was also essential in increasing survival after cryopreservation. Among the various media and treatment durations evaluated, a 24h-preculture of embryonic axes on medium with 0.3M sucrose and 0.5M glycerol was found to be optimal. Using these pregrowth and preculture conditions followed by treatment at 25 degrees C for 20 min each with a loading solution (0.4M sucrose + 2.0M glycerol) and then the PVS2 vitrification solution, direct immersion in liquid nitrogen, rapid rewarming, unloading in a 1.2M sucrose solution for 20 min and transfer of embryonic axes on recovery medium, 82.5% survival and regrowth without intermediary callus formation were obtained with C. madurensis embryonic axes.
Synergistic sonoelectrochemical removal of substituted phenols: implications of ultrasonic parameters and physicochemical properties

Kim K, Cho E, Thokchom B, Cui M, Jang M, Khim J

Ultrason Sonochem, 2015 May;24:172-7.
PMID: 25432401 DOI: 10.1016/j.ultsonch.2014.11.004

The effects of ultrasonic conditions and physicochemical properties on the synergistic degradation in synthetic solution were investigated. A wide range of ultrasound frequencies, including 35, 170, 300, 500 and 700 kHz, and ultrasonic power densities, including 11.3, 22.5 and 31.5 W/L were used. It was revealed that the physical effect of ultrasound plays a major role in synergistic mechanism and 35 kHz was found to be the most effective frequency due to its more vigorous physical effect induced by high implosive energy released from collapse of cavitation bubbles. The highest ultrasonic power density (31.5 W/L) showed the highest synergy index as it increases the number of cavitation bubbles and the energy released when they collapse. The synergy indexes of various substituted phenols under identical condition were investigated. These results were correlated with physicochemical properties, namely octanol-water partition coefficient (Log K OW), water solubility (SW), Henry's law constant (KH) and water diffusivity (DW). Among these parameters, Log K OW and DW were found to have substantial effects on synergy indexes.
Arsenite removal using a pilot system of ultrasound and ultraviolet followed by microfiltration

Cui M, Jang M, Ibrahim S, Park B, Cho E, Khim J

Ultrason Sonochem, 2014 Jul;21(4):1527-34.
PMID: 24500068 DOI: 10.1016/j.ultsonch.2014.01.001

Batch and continuous-flow pilot tests using ultrasound (US), ultraviolet (UV) and a combination of US and UV were conducted to determine the oxidation rates of arsenite [As(III)]. Compared to the single processes of US or UV, the combined US/UV system was more effective for As(III) oxidation with a synergy index of more than 1.5. A high rate constant of As(III) removal was obtained as ferrous [Fe(II)] ions existed. Like the pseudo-Fenton reaction, Fe(II) species can participate in the production of additional ·OH by reacting with H2O2 produced by US, before being oxidized to Fe(III). From the results of batch tests, the optimum molar ratio of Fe(II)/As(III) and pH were found to be 83 and 6-9.5, respectively. Similarly, the continuous-flow pilot tests showed that US/UV system could remove As(III) below the regulation [10 μg L(-1) as total As (Astot)] at 91 of molar ratio [Fe(II)/As(III)] and 3-h HRT. The continuous-stirred-tank-reactor (CSTR) modeling showed that the scavenging effect of anionic species (Cl(-) and CO3(2-)) for ·OH might prevail in the single processes, whereas it is insignificant in the combined process. Without using chemicals, microfiltration (MF) was adopted to treat sludge produced in oxidation step. In terms of an engineering aspect, the operational critical flux (CF) and cycle time were also optimized through the continuous-flow tests of MF system. As an energy-utilizing oxidation technique that does not require a catalyst, the combined energy system employing US/UV followed by MF could be a promising alternative for treating As(III) and Fe(II) simultaneously.
Fulltext Corrigendum re "Genetic Variants Related to Longer Telomere Length are Associated with Increased Risk of Renal Cell Carcinoma" [Eur Urol 2017;72:747-54]

Machiela MJ, Hofmann JN, Carreras-Torres R, Brown KM, Johansson M, Wang Z, et al.

Eur Urol, 2018 Sep;74(3):e85-e86.
PMID: 29853305 DOI: 10.1016/j.eururo.2018.05.017
Fulltext Genetic Variants Related to Longer Telomere Length are Associated with Increased Risk of Renal Cell Carcinoma

Machiela MJ, Hofmann JN, Carreras-Torres R, Brown KM, Johansson M, Wang Z, et al.

Eur Urol, 2017 Nov;72(5):747-754.
PMID: 28797570 DOI: 10.1016/j.eururo.2017.07.015

BACKGROUND: Relative telomere length in peripheral blood leukocytes has been evaluated as a potential biomarker for renal cell carcinoma (RCC) risk in several studies, with conflicting findings.
OBJECTIVE: We performed an analysis of genetic variants associated with leukocyte telomere length to assess the relationship between telomere length and RCC risk using Mendelian randomization, an approach unaffected by biases from temporal variability and reverse causation that might have affected earlier investigations.
DESIGN, SETTING, AND PARTICIPANTS: Genotypes from nine telomere length-associated variants for 10 784 cases and 20 406 cancer-free controls from six genome-wide association studies (GWAS) of RCC were aggregated into a weighted genetic risk score (GRS) predictive of leukocyte telomere length.
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Odds ratios (ORs) relating the GRS and RCC risk were computed in individual GWAS datasets and combined by meta-analysis.
RESULTS AND LIMITATIONS: Longer genetically inferred telomere length was associated with an increased risk of RCC (OR=2.07 per predicted kilobase increase, 95% confidence interval [CI]:=1.70-2.53, p<0.0001). As a sensitivity analysis, we excluded two telomere length variants in linkage disequilibrium (R2>0.5) with GWAS-identified RCC risk variants (rs10936599 and rs9420907) from the telomere length GRS; despite this exclusion, a statistically significant association between the GRS and RCC risk persisted (OR=1.73, 95% CI=1.36-2.21, p<0.0001). Exploratory analyses for individual histologic subtypes suggested comparable associations with the telomere length GRS for clear cell (N=5573, OR=1.93, 95% CI=1.50-2.49, p<0.0001), papillary (N=573, OR=1.96, 95% CI=1.01-3.81, p=0.046), and chromophobe RCC (N=203, OR=2.37, 95% CI=0.78-7.17, p=0.13).
CONCLUSIONS: Our investigation adds to the growing body of evidence indicating some aspect of longer telomere length is important for RCC risk.
PATIENT SUMMARY: Telomeres are segments of DNA at chromosome ends that maintain chromosomal stability. Our study investigated the relationship between genetic variants associated with telomere length and renal cell carcinoma risk. We found evidence suggesting individuals with inherited predisposition to longer telomere length are at increased risk of developing renal cell carcinoma.