Manganese and iron oxides on pipe surface promote dissolved aluminum accumulation in drinking water distribution systems.

Aluminum-containing deposits are pervasive in drinking water distribution systems (DWDSs). However, the mechanisms driving dissolved Al transformation to pipe deposits remain elusive. This study investigated dissolved Al accumulation in DWDSs by batch experiments and long-term pipe experiments using actual finished water. PVC pipe experiments showed that dissolved Al hardly deposited on clean PVC pipe walls at alkaline pH. However, it could be substantially anchored by the pipe surface covered with Mn and Fe deposits formed from Mn(II) oxidation and Fe(III) precipitation. Batch experiments verified that the synthesized Mn and Fe oxides exhibited a strong capacity for dissolved Al uptake at pH 7.7 and 9.0 (dissolved Al was the dominant form). Biofilms on pipe walls also enhanced dissolved Al accumulation. Iron pipe experiments showed that corroded iron pipes with abundant iron corrosion products readily accumulated Al. Compared to chlorination and chloramination, non-disinfected conditions were more favorable for particulate Al deposition on iron pipe surface, probably due to Al immobilization by biofilms. In addition, continuous Al accumulation in iron pipes enhanced Fe release to pipe water. This study highlighted the important role of metal oxides in dissolved Al accumulation in DWDSs with abundant Mn and Fe solids, which provided new insights into deposit formation and control strategies.

Corroded iron pipe inhibits microbial-mediated Mn(II) oxidation and MnOx accumulation compared to PVC pipe.

MnOx deposits in distribution pipes can cause severe discoloration problems in drinking water. However, the impact of pipe materials on Mn(II) oxidation and MnOx accumulation remains unclear. This study investigated microbial-mediated Mn(II) oxidation and deposit formation through 300-day pipe loop experiments with corroded galvanized steel pipes (DN100) and new polyvinyl chloride (PVC) pipes (DN100). The results showed that influent Mn(II) was entirely oxidized within 48 h in the PVC pipes with biofilms in the absence of chlorine, while most influent Mn(II) remained unoxidized in the iron pipes. Dissolved oxygen (DO) monitoring showed that the DO in the PVC pipes was consistently higher than 8.0 mg/L, but that in the iron pipes dropped to 6.5 mg/L. Microbial analysis revealed that the abundance of potential Mn(II)-oxidizing bacteria in the low-DO iron pipes was less than that in the PVC pipes. Analysis of the Mn(II) concentration dynamics in different pipes revealed that the early Mn(II) disappearance in the iron pipes was contributed mainly to Mn(II) adsorption by iron corrosion products rather than microbial Mn(II) oxidation. When aeration was performed to increase the DO concentration to 8.0 mg/L in the iron pipes, complete Mn(II) oxidation occurred. This study provides insights into Mn(II) transformation in different pipes and highlights the critical role of DO in microbial Mn(II) oxidation in drinking water pipes.

MIB-derived odor management based upon hydraulic regulation in small drinking water reservoirs: Principle and application.

The musty odorant (2-methylisoborneol, MIB) is prevalent in source water reservoirs and has become one of the major challenges for drinking water quality. This study proposes an approach to control the growth of MIB-producing cyanobacteria in a small reservoir based on hydraulic regulation, according to the results of long-term field investigations, laboratory culture experiments, model construction, and field application. Field investigations found that longer hydraulic retention time (HRT) is a factor that triggers MIB episodes. The culture study revealed that the maximum cell density, growth rate of MIB-producing Planktothricoides raciborskii, and MIB concentration are determined by the HRT (R2= 0.94, p-value < 0.001) and can be minimized by decreasing the HRT to less than 10 d. On this basis, an HRT regulation model was constructed and validated by field investigation, and critical HRT values were evaluated for 14 cyanobacteria genera. By decreasing the HRT to 5.4 ± 0.8 d, which is lower than the critical value of 7.5 ∼ 15.0 d, an MIB episode was successfully terminated in ZXD Reservoir in 2021. The results suggest that the proposed principle can provide a scientific basis for HRT regulation, which has been proved to be effective and feasible. This approach avoids negative impacts on water quality, does not require extra investment in engineering infrastructure, and in some cases may be applied readily by changing existing operational procedures. Therefore, HRT-based regulation is a promising strategy targeting MIB control and possibly for other cyanobacterial-derived water quality problems in small reservoirs.

Pore-Scale Study on Shale Oil-CO2-Water Miscibility, Competitive Adsorption, and Multiphase Flow Behaviors.

Due to the fracturing fluid imbibition and primary water, oil-water two-phase fluids generally exist in shale nanoporous media. The effects of water phase on shale oil recovery and geological carbon sequestration via CO2 huff-n-puff is non-negligible. Meanwhile, oil-CO2 miscibility after CO2 huff-n-puff also has an important effect on oil-water two-phase flow behaviors. In this work, by considering the oil-CO2 competitive adsorption behaviors and the effects of oil-CO2 miscibility on water wettability, an improved multicomponent and multiphase lattice Boltzmann method is proposed to study the effects of water phase on CO2 huff-n-puff. Additionally, the effects of oil-CO2 miscibility on oil-water flow behaviors and relative permeability are also discussed. The results show that due to Jamin's effect of water droplets in oil-wetting pores and the capillary resistance of bridge-like water phase in water-wetting pores, CO2 can hardly diffuse into the oil phase, causing a large amount of remaining oil. As water saturation increases, Jamin's effect and the capillary resistance become more pronounced, and the CO2 storage mass gradually decreases. Then, based on the results from molecular dynamics simulations, the influences of oil-CO2 miscibility on oil-water relative permeability in calcite nanoporous media are studied, and as the oil mass percentage in the oil-CO2 miscible system decreases, the oil/water relative permeability decreases/increases. The improved lattice Boltzmann model can be readily extended to quantitatively calculate geological CO2 storage mass considering water saturation and calculate the accurate oil-water relative permeability based on the real 3D digital core.

Efficient Mn(II) removal by biological granular activated carbon filtration.

Sufficient and sustainable manganese(II) removal is a challenging task to prevent Mn-related drinking water discoloration problems. This study investigated Mn(II) removal by granular activated carbon (GAC) filtration under various conditions. The results showed that biological GAC filter columns could reduce Mn(II) from 400 µg/L to 10 µg/L after a short ripening period, while sand filter columns did not show evident Mn(II) removal function. Water quality changes, pretreatment with NaClO and chemogenic MnOx coating on GAC media surface did not influence the Mn(II) removal capacity of GAC filter columns. 16S rRNA gene sequencing showed that the abundance of potential Mn(II)-oxidizing bacteria in the GAC media was similar to that in the sand media. However, qPCR results indicated that GAC media colonized dramatically more biomass than sand media, resulting in highly effective Mn(II) removal by GAC filter columns. Under chlorinated conditions, GAC filtration underperformed sand filtration in Mn(II) removal, although activated carbon has been reported to be capable of catalyzing Mn(II) oxidation by chlorine. Fast chlorine decay in GAC filter columns made it hard to sustain chemical Mn(II) oxidation and thus led to less Mn(II) removal. This study highlighted the advantage of biological GAC filtration over sand filtration in Mn(II) removal.

Biosynthesis of 2-methylisoborneol is regulated by chromatic acclimation of Pseudanabaena.

Cyanobacteria can sense different light color by adjusting the components of photosynthetic pigments including chlorophyll a (Chl a), phycoerythrin (PE), and phycocyanin (PC), etc. Filamentous cyanobacteria are the main producer of 2-methylisoborneol (MIB) and many can increase their PE levels so that they are more competitive in subsurface layer where green light is more abundant, and have caused extensive odor problems in drinking water reservoirs. Here, we identified the potential correlation between MIB biosynthesis and ambient light color induced chromatic acclimation (CA) of a MIB-producing Pseudanabaena strain. The results suggest Pseudanabaena regulates the pigment proportion through Type III CA (CA3), by increasing PE abundance and decreasing PC in green light. The biosynthesis of MIB and Chl a share the common precursor, and are positively correlated with statistical significance regardless of light color (R2=0.68; p<0.001). Besides, the PE abundance is also positively correlated with Chl a in green light (R2=0.57; p=0.019) since PE is the antenna that can only transfer the energy to PC and Chl a. In addition, significantly higher MIB production was observed in green light since more Chl a was synthesized.

Chloramine Prevents Manganese Accumulation in Drinking Water Pipes Compared to Free Chlorine by Simultaneously Inhibiting Abiotic and Biotic Mn(II) Oxidation.

The oxidation of residual Mn(II) in finished water can lead to MnOx deposit formation in drinking water pipes. Previous work has illustrated that microbes readily cause Mn deposit build-up in nondisinfected pipes. Here, we investigated how disinfectant type and dose affected Mn(II) oxidation and MnOx accumulation through long-term pipe experiments using water produced by a full-scale water treatment plant. The results showed that Mn(II) oxidation initiated quickly in the new pipes chlorinated with 1.0 mg/L free chlorine. After 130 days of MnOx accumulation, 100 µg/L Mn(II) in water could drop to 1.0 µg/L within 1.5 h, resulting from autocatalytic Mn(II) oxidation and Mn(II) adsorption by MnOx deposits accumulated on pipe walls. In contrast to chlorination, chloramination (1.0 mg/L Cl2) caused almost no MnOx accumulation during the entire study period. The underlying mechanism was probably that monochloramine inhibited microbial Mn(II) oxidation without causing significant abiotic Mn(II) oxidation like free chlorine. A low free chlorine dose (0.3 mg/L) also reduced Mn deposit formation by mass but to a lesser extent than chloramination. After disinfection (chlorination or chloramination) was discontinued for days, biotic Mn(II) oxidation occurred, and this process was inhibited again once disinfection was resumed. In addition, Fe(III) of 200 µg/L enhanced the stability of MnOx accumulated on pipe surfaces, while humic acid induced MnOx deposit resuspension. Overall, this study highlighted the regulating role of disinfectants in MnOx formation and provided insights into developing appropriate disinfection strategies for Mn deposit control.

Darbepoetin alfa injection versus epoetin alfa injection for treating anemia of Chinese hemodialysis patients with chronic kidney failure: A randomized, open-label, parallel-group, non-inferiority Phase III trail.

Background: Erythropoietin is a glycoprotein that mainly regulates erythropoiesis. In patients with chronic renal failure with anemia, darbepoetin alfa can stimulate erythropoiesis, correct anemia, and maintain hemoglobin levels. This study was designed to demonstrate the efficacy and safety of darbepoetin alfa injections as being not inferior to epoetin alfa injections (Recombinant Human Erythropoietin injection, rHuEPO) when maintaining hemoglobin (Hb) levels within the target range (10.0-12.0 g/dL) for the treatment of renal anemia. Methods: Ninety-five patients were enrolled in this study from April 15, 2013 to April 10, 2014 at 25 sites. In this study, patients (n = 95) aged 18-70 years were randomized into a once per week intravenous darbepoetin alfa group (n = 56) and a twice or three times per week intravenous epoetin alfa group (n = 39) for 28 weeks, who had anemia with hemoglobin levels between 6 g/dL and 10 g/dL due to chronic kidney disease (CKD) and were undergoing hemodialysis or hemofiltration with ESA-naive (erythropoiesis stimulating agent-naive). The primary efficacy profile was the mean Hb level (the non-inferiority margin was -1.0 g/dL, week 21-28); the secondary efficacy profiles were the Hb increase rate (week 0-4), the target Hb achievement cumulative rate and time, the change trends of the Hb levels, and the target Hb maintenance ratio. Adverse events (AEs) were observed and compared, and the efficacy and safety were analyzed between the two treatment groups. Additionally, the frequencies of dose adjustments between the darbepoetin alfa and epoetin alfa groups were compared during the treatment period. SAS® software version 9.2 was used to perform all statistical analyses. Descriptive statistics were used for all efficacy, safety, and demographic variable analyses, including for the primary efficacy indicators. Results: The mean Hb level was 11.3 g/dL in the darbepoetin alfa group and 10.7 g/dL in the epoetin alfa group, respectively; the difference of the lower limits of the 95% confidence intervals (CI) between the two groups was 0.1 g/dL (>-1.0 g/dL), and non-inferiority was proven; the Hb levels started to increase in the first four weeks at a similar increase rate; no obvious differences were observed between the groups in the target Hb achievement cumulative rates, and the Hb levels as well as the target Hb level maintenance rate changed over time. The incidence of AEs was 62.5% in the darbepoetin alfa group and 76.9% in the epoetin alfa group. All the adverse events observed in the study were those commonly associated with hemodialysis. Conclusion: Darbepoetin alfa intravenously once per week can effectively increase Hb levels and maintain the target Hb levels well, which makes it not inferior to epoetin alfa intravenously twice or three times per week. Darbepoetin alfa shows an efficacy and safety comparable to epoetin alfa for the treatment of renal anemia.

Driving forces for the growth of MIB-producing Planktothricoides raciborskii in a low-latitude reservoir.

In comparison with the middle- and high-latitude regions, the low-latitude regions are less associated with the occurrence of 2-methylisoborneol (MIB) episodes, since most of the previously identified MIB producers favor moderate/low light/temperature conditions. Here, we report a serious MIB outbreak over the period from Jul. 2018 to Jun. 2019 in a low-latitude reservoir with a mean annual water temperature of 25.6 °C. The MIB episode lasted for a long period, from Jul. 2018 to Jan. 2019, and Planktothricoides raciborskii was confirmed to be the main MIB producer. The growth characteristics of P. raciborskii were explored through both laboratory culturing and on-site verification experiments. The results indicated that this strain was not nutrient-sensitive at TN > 800 µg L-1 and TP > 10 µg L-1, but favored moderate light intensity (54 µmol photon m-2·s-1) and high temperature (30 °C). The two bloom-forming genera, Limnothrix and Aphanizomenon, favoring lower temperature and similar or relatively higher light intensity, showed much greater proliferation, about 13 folds (Limnothrix) and 58 folds (Aphanizomenon), from Dec. to Jun.; by contrast, the high water temperature (29.9 ± 2.8 °C) and light intensity (189.1 ± 87.6 µmol photon m-2·s-1) from Jul. to Nov. were not favorable to Limnothrix or Aphanizomenon, which might have created an opportunity for the growth of MIB-producing P. raciborskii. In addition, we also found that high temperature could promote the release of MIB from P. raciborskii cells, therefore exerting increased pressure on drinking water treatment processes.

Initial Formation and Accumulation of Manganese Deposits in Drinking Water Pipes: Investigating the Role of Microbial-Mediated Processes.

Microbial Mn(II) oxidation occurs in areas with insufficient disinfectants in drinking water distribution systems. However, the overall processes of microbial-mediated Mn deposit formation are unclear. This research investigated the initial Mn(II) oxidation, deposit accumulation, and biofilm development in pipe loops fed with nondisinfected finished water for 300 days. The results show that it took 20 days for microbial Mn(II) oxidation and deposition to be initiated visibly in new pipes continuously receiving 100 µg/L Mn(II). Once started, the deposit accumulation accelerated. A pseudo-first-order kinetic model could simulate the disappearance of Mn(II) in well-mixed pipe loop water. The observed rate constant reached 2.81 h-1 [corresponding to a Mn(II) half-life of 0.25 h] after 136 days of operation. Without oxygen, Mn(II) in the water also decreased rapidly to 1.0 µg/L through adsorption to deposits, indicating that after the initial microbial formation of MnOx, subsequent MnOx accumulation was attributable to a combination of microbial and physicochemical processes. Compared to the no-Mn condition, Mn(II) input resulted in 1 order of magnitude increase in biofilm formation. This study sheds light on the increasingly rapid processes of Mn accumulation on the inner surfaces of water pipes resulting from the biological activity of Mn(II)-oxidizing biofilms and the build-up of MnOx with strong adsorption capacity.

Identifying the function of activated carbon surface chemical properties in the removability of two common odor compounds.

In this study, the adsorption capacities of two common odor compounds, 2-methylisoborneol (2-MIB) and dimethyl disulfide (DMDS), onto nine common types of powdered activated carbon (PAC) were comprehensively compared to screen the critical surface chemical properties affecting the adsorption performance. The results showed that the adsorption capacities of all the PACs for DMDS were generally lower than those for 2-MIB. The Spearman's rank correlation analysis indicated that the adsorption capacity for 2-MIB did not have any correlation with the PAC surface sites, while the DMDS adsorption capacity was positively related to the number of basic sites. The effect of the PAC basic sites on the DMDS adsorption was further verified by density functional theory (DFT) calculation in two adsorption modes (facial mode and edge mode). The graphene structure in the edge mode was the most favorable for DMDS adsorption with the lowest adsorption enthalpy, followed by the ketone-doped structure under the facial mode. An independent gradient model indicated that van der Waals forces were dominant in the DMDS adsorption. Moreover, thermal modification was conducted to further prove the relationship between the basic sites and the DMDS adsorption. After thermal modification, the PAC with more basic sites and graphene structures was found to be more effective for DMDS adsorption. Overall, this study could offer guidance for water treatment plants with respect to the selection of PAC to solve the odor problems caused by various compounds (e.g., DMDS or 2-MIB), and the modification of PAC, aiming at more efficient odor removal.

Experimental investigation of shale oil recovery from Qianjiang core samples by the CO2 huff-n-puff EOR method.

CO2 Huff-n-Puff (HnP) is an effective technique for enhancing oil recovery (EOR) that can be applied to shale oil reservoirs faced with poor natural productivity and low water injectivity. The main objective of this study is to investigate the interactions of CO2 and formation crude oil, and evaluate the CO2 HnP performance in shale oil reservoirs in the Qianjiang depression in China. In this study, the variation rules of oil phase behavior, viscosity, saturation pressure, and swelling factor at different CO2 contents of 0 to 65% were studied. A series of HnP experiments were conducted. The factors affecting the oil recovery were discussed, and Nuclear Magnetic Resonance (NMR) tests were conducted on core samples at different stages of the HnP process. The results show that the injected CO2 can make an positive change in the crude oil phase behavior. The oil-gas two-phase region enlarges and the saturation pressure increases as more CO2 is dissolved in the formation oil, which is beneficial to oil production. The dissolution of CO2 in the oil phase increased the oil swelling degree by 1.492 times, and the viscosity decreased from 1.944 to 0.453 mPa s. The HnP experimental results demonstrate that the soaking time should be determined based on the injection pressure. Miscible conditions is a viable option for CO2 HnP as 10% more oil can be produced using miscible HnP and save more than half of the soaking time. The results illustrate that fracture is the most important factor affecting oil recovery, and the performance of HnP EOR on core samples with fractures is almost 25% better than those without fractures. However, the core matrix permeability has an almost negligible effect on the performance of CO2 HnP. The NMR tests show that the oil recovered in the first cycle was dominated by macropores and mesopores, followed by small pores. In the latter HnP cycles, the oil in small pores and micropores becomes the main oil-producing area. This study may provide a better understanding of the CO2 HnP enhanced recovery strategy for shale reservoirs.

DNA Repair Gene Polymorphisms in Relation to Non-Small Cell Lung Cancer Survival.

BACKGROUND: Single nucleotide polymorphisms (SNPs) in the DNA repair genes are suspected to be related to the survival of lung cancer patients due to their possible influence on DNA repair capacity (DRC). However, the study results are inconsistent. METHODS: A follow-up study of 610 non-small cell lung cancer (NSCLC) patients was conducted to investigate genetic polymorphisms associated with the DNA repair genes in relation to NSCLC survival; 6 SNPs were genotyped, including XRCC1 (rs25487 G>A), hOGG1 (rs1052133 C>G), MUTYH (rs3219489 G>C), XPA (rs1800975 G>A), ERCC2 (rs1799793 G>A) and XRCC3 (rs861539 C>T). Kaplan- Meier survival curve and Cox proportional hazards regression analyses were performed. SNP-SNP interaction was also examined using the survival tree analysis. RESULTS: Advanced disease stage and older age at diagnosis were associated with poor prognosis of NSCLC. Patients with the variant 'G' allele of hOGG1 rs1052133 had poor overall survival compared with those with the homozygous wild 'CC' genotype, especially in female patients, adenocarcinoma histology, early stage, light smokers and without family history of cancer. For never smoking female lung cancer patients, individuals carrying homozygous variant 'AA' genotype of XPA had shorter survival time compared to those with wild 'G' alleles. Furthermore, females carrying homozygous variant XPA and hOGG1 genotypes simultaneously had 2.78-fold increased risk for death. Among all 6 polymorphisms, the homozygous variant 'AA' of XPA carriers had poor prognosis compared to the carriers of wild 'G' alleles of XPA together with other base excision repair (BER) polymorphisms. CONCLUSIONS: Besides disease stage and age, the study found DNA repair gene polymorphisms were associated with lung cancer survival.

Theoretical Analysis of the Mechanism of Fracture Network Propagation with Stimulated Reservoir Volume (SRV) Fracturing in Tight Oil Reservoirs.

Stimulated reservoir volume (SRV) fracturing in tight oil reservoirs often induces complex fracture-network growth, which has a fundamentally different formation mechanism from traditional planar bi-winged fracturing. To reveal the mechanism of fracture network propagation, this paper employs a modified displacement discontinuity method (DDM), mechanical mechanism analysis and initiation and propagation criteria for the theoretical model of fracture network propagation and its derivation. A reasonable solution of the theoretical model for a tight oil reservoir is obtained and verified by a numerical discrete method. Through theoretical calculation and computer programming, the variation rules of formation stress fields, hydraulic fracture propagation patterns (FPP) and branch fracture propagation angles and pressures are analyzed. The results show that during the process of fracture propagation, the initial orientation of the principal stress deflects, and the stress fields at the fracture tips change dramatically in the region surrounding the fracture. Whether the ideal fracture network can be produced depends on the geological conditions and on the engineering treatments. This study has both theoretical significance and practical application value by contributing to a better understanding of fracture network propagation mechanisms in unconventional oil/gas reservoirs and to the improvement of the science and design efficiency of reservoir fracturing.

Prognostic implications for high expression of MiR-25 in lung adenocarcinomas of female non-smokers.

BACKGROUND: Adenocarcinoma (ADC) is the most common histological type of lung cancer and its proportion is rising, especially in Asian non-smoking women. Recent studies suggest miR-25 may have diverse effects on the pathogenesis of different types of cancer. However, the role of miR-25 in lung cancer is still unknown. The aim of this study was to investigate the potential clinical value of miR-25 in non-smoking women with lung ADC. PATIENTS AND METHODS: Quantitative RT-PCR was performed to evaluate the expression of miR-25 in 100 lung ADC tumor tissues and matched plasma samples and Pearson correlation tests were used to analyze the relationship between values. Associations of miR-25 expression with clinicopathological features were determined using the Student's t-test. To determine prognostic value, overall survival (OS) was evaluated using the Kaplan-Meier method. Univariate and multivariate analyses were performed using the Cox proportional hazard model. RESULTS: Expression of miR-25 in tissue was found to be associated with lymph node metastasis (P=0.021) and disease stage (P=0.012). Moreover, high miR-25 expression was also associated with poorer overall survival of women with lung ADC (P=0.008). CONCLUSION: Tissue miR-25 expression may be associated with tumor progression and have prognostic implications in female lung ADC patients.

Circulating microRNAs in relation to EGFR status and survival of lung adenocarcinoma in female non-smokers.

OBJECTIVES: Lung adenocarcinoma is considered a unique disease for Asian female non-smokers. We investigated whether plasma microRNA (miRNA) expression profiles are different by the EGFR status and are associated with survival outcomes of the patients. METHODS: Using real-time RT-PCR, we analyzed the expression of 20 miRNAs in the plasma of 105 female patients with lung adenocarcinoma. Kaplan-Meier survival analysis and Cox proportional hazards regression were performed to determine the association between miRNA expression and overall survival. Time dependent receiver operating characteristic (ROC) analysis was also performed. RESULTS: In the 20 miRNAs, miR-122 were found differently expressed between wild and mutant EGFR carriers (P=0.018). Advanced disease stage and tumor metastasis were independently associated with poor prognosis of patients with lung adenocarcinoma (P=0.010 and 1.0×10(-4)). Plasma levels of miR-195 and miR-122 expression were also associated with overall survival in the patients, especially in those with advanced stage (HR=0.23, 95%CI:0.07-0.84; and HR=0.22, 95%CI:0.06-0.77) and EGFR mutation (HR=0.27, 95%CI:0.08-0.96; and HR=0.23, 95%CI=0.06-0.81). Moreover, a model including miR-195, miR-122 may predict survival outcomes of female patients with lung adenocarcinoma (AUC=0.707). CONCLUSIONS: Circulating miR-195 and miR-122 may have prognostic values in predicting the overall survival as well as predicting EGFR mutation status in non-smoking female patients with lung adenocarcinoma. Measuring plasma levels of miR-195 and miR-122 may especially be useful in EGFR mutant patients with lung adenocarcinoma.

miRNAs in cancer prevention and treatment and as molecular targets for natural product anticancer agents.

MicroRNAs (miRNAs) are endogenous small non-coding RNAs that regulate gene expression by binding to the 3´untranslated region of target mRNA, resulting in posttranscriptional gene silencing via mRNA degradation or translation inhibition. miRNAs are involved in many biological processes including carcinogenesis. They can act as oncogenes or tumor suppressors and their aberrant expressions are intimately linked with cancer development and progression. Therefore, miRNAs have been utilized as potential biomarkers for cancer diagnosis, prognosis, as well as cancer therapeutic targets. Recently, it has been demonstrated that dietary and natural chemopreventive agents exert their anticancer activities through the regulation of one or more miRNAs. In addition to expounding the latest findings of miRNAs in cancer, this review also discusses the recent efforts on the translational research of miRNAs, with an emphasis on natural products in the treatment of cancer.

Meta-Analysis of the Association between Mir-196a-2 Polymorphism and Cancer Susceptibility.

OBJECTIVE: MicroRNA plays a vital role in gene expression, and microRNA dysregulation is involved in carcinogenesis. The miR-196a-2 polymorphism rs11614913 is reportedly associated with cancer susceptibility. This meta-analysis was performed to assess the overall association of miR-196a-2 with cancer risk. METHODS: A total of 27 independent case-control studies involving 10,435 cases and 12,075 controls were analyzed for the rs11614913 polymorphism. RESULTS: A significant association was found between rs11614913 polymorphism and cancer risk in four genetic models (CT vs. TT, OR=1.15, 95%CI=1.05-1.27; CC vs. TT, OR=1.23, 95%CI=1.08-1.39; Dominant model, OR=1.17, 95%CI=1.06-1.30; Additive model, OR=1.08, 95%CI=1.01-1.14). In the subgroup analysis of different tumor types, the C allele was associated with increased risk of lung, breast, and colorectal cancer, but not with liver, gastric, or esophageal cancer. In the subgroup analysis by ethnicity, a significantly increased risk of cancer was found among Asians in all genetic models, but no associations were found in the Caucasian subgroup. CONCLUSIONS: The meta-analysis demonstrated that the miR-196a-2 polymorphism is associated with cancer susceptibility, especially lung cancer, colorectal cancer, and breast cancer among Asian populations.

Sleep behavior disorders in a large cohort of chinese (Taiwanese) patients maintained by long-term hemodialysis.

BACKGROUND: Disorders of sleep behavior and sleep-related breathing disorders are common in hemodialysis patients. Most such evidence is based on studies involving small numbers of patients. METHODS: We undertook a large multicenter analysis of sleep behavior in more than 700 Taiwanese patients on maintenance hemodialysis therapy for 6 months to 20-plus years by using self-administered questionnaires: the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, and Berlin Questionnaire for risk for sleep apnea, validated for the general population. Patients also completed a questionnaire to assess symptoms related to restless legs and periodic limb movements (PLMs). Sleep behavior was analyzed in relation to demographic and dialysis-related parameters provided by the participating dialysis centers. RESULTS: Sleep disturbance was very common in this cohort, with problems of insomnia (66.6%) exceeding those related to daytime sleepiness (17.8%). Sleep disturbances were associated with restless legs syndrome (RLS)/PLM and a high risk for sleep apnea, determined by using the Berlin Questionnaire. Older age increased the odds of daytime sleepiness, but not insomnia. Lower dialysis dose (single-pool Kt/V) increased the likelihood of daytime sleepiness and was associated with greater rates for RLS/PLM and risk for sleep apnea. Use of antihypertensive medications (a probable surrogate for more severe hypertension) was associated strongly with high risk for sleep apnea. Smoking was associated with RLS/PLM and risk for sleep apnea, whereas consumption of stimulant beverages (coffee and tea) had contrary effects on RLS/PLM and risk for sleep apnea and were not implicated in measures of insomnia or daytime sleepiness. A greater likelihood of insomnia for greater hemoglobin levels and greater likelihood of daytime sleepiness for patients administered vitamin D analogues were not explained by the available data. CONCLUSION: Sleep disorders and sleep-related breathing disorders are common in hemodialysis patients. Greater attention in the care of dialysis patients needs to be directed to the diagnosis and management of sleep disorders.