Association of serum uric acid with anemia in U.S. adults: a cross-sectional study using secondary data.

BACKGROUND: High serum uric acid (SUA) is a risk factor of cardiovascular disease (CVD). Abnormal SUA have been correlated with a significant increase in mortality. Anemia is an independent predictor of mortality and CVD. To date, no study has investigated the relationship between SUA and anemia. Here, we explored the correlation between SUA and anemia in the American population. METHODS: The cross-sectional study involved 9205 US adults from NHANES (2011-2014). The relationship between SUA and anemia was explored using multivariate linear regression models. Two-piecewise linear regression model, generalized additive models (GAM) and smooth curve fitting were performed to explore the non-linear relationships between SUA and anemia. RESULTS: We found a U-shaped non-linear relationship between SUA and anemia. The inflection point of the SUA concentration curve was 6.2 mg/dL. The ORs (95% CIs) for anemia on the left and right of the inflection point were 0.86 (0.78-0.95) and 1.33 (1.16-1.52), respectively. The 95% CI of inflection point was 5.9-6.5 mg/dL. The findings showed that both genders presented a U-shaped correlation. Safe ranges of SUA in men and women were 6-6.5 and 4.3-4.6 mg/dL, respectively. CONCLUSIONS: Both high and low SUA levels were correlated with increased risk of anemia, and a U-shaped relationship was observed between SUA and anemia.

A label-free T4 polynucleotide kinase fluorescence sensor based on split dimeric G-quadruplex and ligation-induced dimeric G-quadruplex/thioflavin T conformation.

The phosphorylation process of DNA by T4 polynucleotide kinase (T4 PNK) plays a crucial role in DNA recombination, DNA replication, and DNA repair. Traditional monomeric G-quadruplex (G4) systems are always activated by single cation such as K+ or Na+. The conformation transformation caused by the coexistence of multiple cations may interfere with the signal readout and limit their applications in physiological system. In view of the stability of dimeric G4 in multiple cation solution, we reported a label-free T4 PNK fluorescence sensor based on split dimeric G4 and ligation-induced dimeric G4/thioflavin T (ThT) conformation. The dimeric G4 was divided into two independent pieces of one normal monomeric G4 and the other monomeric G4 fragment phosphorylated by T4 PNK in order to decrease the background signal. With the introduction of template DNA, DNA ligase, and invasive DNA, the dimeric G4 could be generated and liberated to combine with ThT to show obvious fluorescence signal. Using our strategy, the linear range from 0.005 to 0.5 U mL-1, and the detection limit of 0.0021 U mL-1 could be achieved without the consideration of interference caused by the coexistence of multiple cations. Additionally, research in real sample determination and inhibition effect investigations indicated its further potential application value in biochemical process research and clinic diagnostics.

Association between dietary inflammatory index score and muscle mass and strength in older adults: a study from National Health and Nutrition Examination Survey (NHANES) 1999-2002.

PURPOSE: Chronic low-grade systemic inflammation affects muscle protein metabolism. The dietary inflammatory index (DII®) is a tool designed to assess the inflammatory potential of the diet. The available data on the association between DII and sarcopenia are limited. We aimed to investigate the association of the DII with components of sarcopenia in individuals over 50 years of age. METHODS: This cross-sectional study used the National Health and Nutrition Examination Survey (NHANES) 1999-2002 dataset. Body composition was measured, and isokinetic strength of the knee extensors (peak force) was evaluated. Low muscle mass and strength were defined using sex-specific thresholds. Energy-adjusted DII (E-DII™) scores were calculated using 24-h dietary recall data. Regression models were fit to evaluate the association between E-DII scores and low muscle mass and low muscle strength, alone and combined. RESULTS: Mean age of study participants was 62.1 ± 9.5 years, and 138 participants (7.4%) belonged to the combination group of low muscle mass and low muscle strength. In multivariable-adjusted regression models, higher E-DII score was associated with lower appendicular skeletal muscle index (ASMI) (ß = - 0.03, P  < 0.001, P trend <0.001), and lower peak force (ß = -2.15, P  = 0.04, P trend = 0.01) and higher likelihood for these components combined (OR = 1.12, 95% CI 1.01-1.25, P = 0.03). CONCLUSION: Higher E-DII score is associated with lower muscle mass and muscle strength, and increased likelihood for the combination of low muscle mass and low muscle strength in older adults. This has important implications for healthy aging.

Label-free fluorescence DNA walker for protein analysis based on terminal protection and dual enzyme assisted cleavage induced G-quadruplex/berberine conformation.

Development of a simple, fast, cost-efficient and sensitive approach for accurate protein analysis is of high significance due to its potential application in disease diagnosis and biomedicine research. Thus, we established a label-free fluorescence DNA walker for streptavidin detection based on terminal protection and dual enzyme assisted cleavage induced G-quadruplex/berberine conformation. In this paper, the swing arm probe and report probe were pre-assembled on gold nanoparticles. With the addition of a target, through the high-efficiency affinity between streptavidin and biotin in order to prevent the hydrolysis of exonuclease I, the swing arm probe which contains 8-17 DNAzyme cannot be destroyed and plays a role in the catalytic cleavage of the report probe, and the liberating fragment of the report probe which contains a specific sequence (5'-(TTAGGG)4) of G-quadruplex units can combine with berberine and shows an evident fluorescence signal enhancement. Our method, a sensitive and selective method of protein detection, achieves a 20 pM detection limit toward streptavidin. This developed DNA walker, which combines terminal protection and a dual enzyme assisted strategy, provides a prospective channel for streptavidin detection and should also be used for the design of biosensors in bio-detection and disease diagnosis.

Retraction of "Porous Organic Polymer-Derived Fe2P@N,P-Codoped Porous Carbon as Efficient Electrocatalysts for pH Universal ORR".

[This retracts the article DOI: 10.1021/acsomega.9b03851.].

Association between appendicular skeletal muscle index and leukocyte telomere length in adults: A study from National Health and Nutrition Examination Survey (NHANES) 1999-2002.

BACKGROUND: A higher body mass index (BMI) is associated with shorter telomeres. The loss of muscle mass with aging is associated with adverse outcomes. The appendicular skeletal muscle index (ASMI) is currently used to quantify muscle mass. OBJECTIVE: We investigated the association of the ASMI with leukocyte telomere length in adult Americans. METHODS: This cross-sectional study used the National Health and Nutrition Examination Survey (NHANES) 1999-2002 dataset. Body composition was measured by dual-energy X-ray absorptiometry. Low muscle mass was defined using sex-specific thresholds of the appendicular skeletal muscle mass index (ASMI). The telomere-to-single-copy gene ratio (T/S ratio) was converted to base pairs. Generalized linear models were performed to evaluate the association of ASMI with telomere length. RESULTS: In multivariable adjustment regression models, higher ASMI was associated with longer telomeres in US adults (ß = 70.2, P < 0.001, P trend<0.001). In participants with preserved muscle mass, the ASMI was related to longer telomere length (ß = 75.1, P < 0.001), but not significantly in low muscle mass participants (ß = 68.7, P = 0.30). Further subgroup analysis by a combination of age groups and muscle mass status showed positive association with young-preserved muscle mass (ß = 82.6, P < 0.001), old-preserved muscle mass (ß = 44.4, P = 0.12), young-low muscle mass (ß = 135.4, P = 0.20), and old-low muscle mass (ß = 52.7, P = 0.55). Because each additional year of chronological age was associated with telomeres that were 15.3 base pairs shorter, on average, this would equate to 5.4 fewer years of biological aging (82.6 ÷ 15.3) in the young-preserved muscle mass participants. CONCLUSIONS: A higher ASMI is associated with longer telomeres. The prevention of skeletal muscle loss has the potential to delay telomere shortening and account for less biological aging.

Porous Organic Polymers as Fire-Resistant Additives and Precursors for Hyperporous Carbon towards Oxygen Reduction Reactions.

Cyclotriphosphazene (CP) based porous organic polymers (POPs) have been designed and prepared. The introduction of CP into the porous skeleton endowed special thermal stability and outstanding flame retardancy to prepared polymers. The nonflammable level of PNK-CMP fabricated via the condensation of 2,2'-(1,4-phenylene)diacetonitrile (DAN) and hexakis(4-acetylphenoxy)cyclotriphosphazene (HACTP) through Knoevenagel reaction, in vertical burning tests reached V-2 class (UL-94) and the limiting oxygen index (LOI) reached 20.8 %. When used as additive, PNK-CMP could suppress the dissolving out of PEPA effectively, reducing environment pollution and improving the flame retardant efficiency. The POP and PEPA co-added PU (mPOP%: mPEPA%=5.0 %: 5.0 %) could not be ignited under simulated real-scale fire conditions. The nonflammable level of POP/PEPA/PU in vertical burning tests (UL-94) reached V-0 class with a LOI as high as 23.2 %. The smoke emission could also be suppressed, thus reducing the potential for flame spread and fire hazards. Furthermore, carbonization of PNK-CMP under the activation of KOH yield a hyperporous carbon (PNKA-800) with ultrahigh BET surface area (3001 m2 g-1) and ultramicropore size showing excellent ORR activity in alkaline conditions.

Porous Organic Polymer-Derived Fe2P@N,P-Codoped Porous Carbon as Efficient Electrocatalysts for pH Universal ORR.

A new porous organic polymer (CP-CMP) was designed and synthesized via the direct polymerization of pyrrole and hexakis(4-formyl-phenoxy)cyclotriphosphazene, skipping the tedious synthetic procedure of porphyrin-monomers containing special groups. This special porous organic polymer (POP) serves as an "all in one" precursor for C, N, P, and Fe. Direct carbonization of this special POP afforded Fe2P@N,P-codoped porous carbons with hierarchical pore structure and high graphitization. Finally, the optimal catalyst (CP-CMP-900) prepared by carbonization of CP-CMP at 900 °C exhibited high efficiency for oxygen electroreduction. Typically, CP-CMP-900 presented an oxygen reduction reaction half-wave potential (E 1/2) of 0.85, 0.73, and 0.65 V, respectively, in alkaline, neutral, and acidic media, close to those of commercial Pt/C in the same electrolyte (0.843, 0.71, and 0.74 V). Furthermore, it also displayed excellent methanol immunity and long-time stability in various electrolytes better than commercial Pt/C (20%).

Highly sensitive detection of T4 polynucleotide kinase activity by coupling split DNAzyme and ligation-triggered DNAzyme cascade amplification.

In current study, a dual strategy for sensitive detection of T4 polynucleotide kinase (T4 PNK) activity was proposed, which combined split DNAzyme-based background reduction with ligation-triggered DNAzyme cascade for signal amplification. The 8-17 DNAzyme is split into two separate oligonucleotide fragments, which can be separately hybridized to the template DNA to form a ligatable nick after one of the fragments is phosphorylated at the 5at the yl by T4 PNK. With the further addition of Escherichia coli DNA ligase, the two oligonucleotides can be ligated to produce the activated 8-17 DNAzyme, the amount of which is positively related to the activity of T4 PNK. The signal amplification can be achieved through the cyclic cleavage of 8-17 DNAzyme toward the molecular beacon substrate, resulting in an evident fluorescence signal enhancement. The current dual strategy can significantly improve the detection sensitivity of the sensing systems, resulting in a detection limit of 0.001 U mL(-1) for T4 PNK activity, which is superior or comparable to the reported methods. Furthermore, the inhibition effects of adenosine diphosphate and sodium hydrogen phosphate on T4 PNK activity have also been demonstrated with satisfactory results. The current method may be further developed as a universal protocol for monitoring activity and inhibition of nucleotide kinase, and may show the huge potentials in biological process researches, drug discovery, and clinic diagnostics.

Enzyme-free and ultrasensitive electrochemical detection of nucleic acids by target catalyzed hairpin assembly followed with hybridization chain reaction.

An isothermal, enzyme-free and ultrasensitive protocol for electrochemical detection of DNA is proposed based on the ingenious combination of target catalyzed hairpin assembly and hybridization chain reaction (HCR) strategies for two-step signal amplification. The DNA hairpin assembly on the electrode is triggered by target DNA, accompanied by the release of target DNA for the successive hybridization and assembly process. The newly emerging DNA fragment on the electrode after hairpin assembly is further used to propagate the HCR between methylene blue-labeled signal probe and auxiliary probe, inducing a remarkably amplified electrochemical signal. The current dual signal amplification strategy is relatively simple and inexpensive owing to avoid the use of any kind of enzyme or sophisticated equipment. It can achieve a sensitivity of 0.1 fM with a wide linear dynamic range from 1 × 10(-15) to 1 × 10(-10)M and discriminate mismatched DNA from perfect matched target DNA with a high selectivity. The high sensitivity and selectivity make this method a great potential for early diagnosis in gene-related diseases.

Amplified detection of DNA by an analyte-induced Y-shaped junction probe assembly followed with a nicking endonuclease-mediated autocatalytic recycling process.

A simple, isothermal and autocatalytic system for the amplified detection of DNA was ingeniously designed based on target-triggered Y-shaped junction probe assembly, followed with a nicking endonuclease-mediated cascade recycling process. A superior detection limit of 0.1 pM towards the target DNA with an excellent selectivity could be achieved.