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I-motifs are four-strand noncanonical secondary structures formed by cytosine (C)-rich sequences in living cells. The structural dynamics of i-motifs play essential roles in many cellular processes, such as telomerase inhibition, DNA repli-cation, and transcriptional regulation. In cells, the structural dynamics of the i-motif can be modulated by the interaction of poly(C)-binding proteins (PCBPs), and the interaction is closely related to human health, through modulating the transcription of oncogenes and telomere stability. Therefore, the mechanisms of how PCBPs interact with i-motif structures are fundamentally important. However, the underlying mechanisms remain elusive. I-motif structures in the promoter of the c-MYC oncogene can be unfolded by heterogeneous nuclear ribonucleoprotein K (hnRNP K), a PCBP, to activate its transcription. Here, we selected this system as an example to comprehensively study the unfolding mechanisms. We found that the promoter sequence containing 5 C-runs preferred folding into type-1245 to type-1234 i-motif structures based on their folding stability, which was further confirmed by single-molecule FRET. In addition, we first revealed that the c-MYC i-motif structure was discretely resolved by hnRNP K through two intermediate states, which were assigned to the opposite hairpin and neighboring hairpin, as further confirmed by site mutations. Furthermore, we found all three KH (hnRNP K homology) domains of hnRNP K could unfold the c-MYC i-motif structure, and KH2 and KH3 were more active than KH1. In conclusion, this study may deepen our understanding of the interactions between i-motifs and PCBPs and may be helpful for drug development. [ABSTRACT FROM AUTHOR]

A robust approach that couples chromatin immunoprecipitation (ChIP) with the paired-end ditag (PET) sequencing strategy for unbiased and precise global localization of transcription-factor binding sites (TFBS) whereby this strategy is applied to map p53 targets in the human genome is described. An unbiased, highly precise, and efficient mapping methodology is presented to allow the whole genome survey of TFBS with an unprecedented resolution.

Telomeres are specific nucleoprotein structures that are located at the ends of linear eukaryotic chromosomes and play crucial roles in genomic stability. Telomere DNA consists of simple repeats of a short G-rich sequence: TTAGGG in mammals and TTTAGGG in most plants. In recent years, the mammalian telomeric G-rich repeats have been shown to form G-quadruplex (G4) structures, which are crucial for modulating telomere functions. Surprisingly, even though plant telomeres are essential for plant growth, development, and environmental adaptions, only few reports exist on plant telomeric G4 DNA (pTG4). Here, using bulk and single-molecule assays, including CD spectroscopy, and single-molecule FRET approaches, we comprehensively characterized the structure and dynamics of a typical plant telomeric sequence, d[GGG(TTTAGGG)3]. We found that this sequence can fold into mixed G4s in potassium, including parallel and antiparallel structures. We also directly detected intermediate dynamic transitions, including G-hairpin, parallel G-triplex, and antiparallel G-triplex structures. Moreover, we observed that pTG4 is unfolded by the AtRecQ2 helicase but not by AtRecQ3. The results of our work shed light on our understanding about the existence, topological structures, stability, intermediates, unwinding, and functions of pTG4. [ABSTRACT FROM AUTHOR]

The Augmentech Body Position Sensor (ABPS), a device for monitoring patient repositioning, was tested for use in morbidly obese patients. Specific aims were to: determine whether there was correspondence between data on patient turning and repositioning from the ABPS and data gathered through human observation; determine whether the ABPS is an acceptable instrument for measuring body movements in morbidly obese patients in terms of ease of use, comfort and ability to stay in place. A descriptive study was conducted. Data from the ABPS recording patients' body positions were compared with data from videotapes taken of the same patients during the same time period. The sleep center of a tertiary care facility in the southeastern United States was used. Ten participants with BMI ≥ 30 were selected from patients referred to the sleep center for polysomnography. Positioning the device on the patient's thigh, data were collected from midnight until discharge. Videotapes taken of the same patient during the same time period were examined for changes in body position over time. There was a strong correspondence between the videotaped data and the ABPS data. The device was comfortable and not irritating to the patient. The APBS can be a useful measure for determining changes in body position but further study should be undertaken to test other sites for placement. [ABSTRACT FROM AUTHOR]

Abstract: Study on the fire hazard and fire safety design of logistics warehouse. Combined with practical work, the fire develops is defined as medium t2 fire in the building and FDS software is used to simulate fire development according to the fire performance-based design. The result shows that the smoke temperature, CO concentration and visibility are safe for human for 884s, and the steel structure is effective during the simulation. For the needs of fire rescue, concrete column and steel structure with fire protection should be applied in the logistic warehouse. Air curtain and windows with 5% area are added in the evacuation exit. [Copyright &y& Elsevier]

Abstract: The coal seams of Late Triassic in Chuxiong Mesozoic Basin had experienced two periods of coalification, one occurring at the foreland basin stage, another at the inland rift stage. The two stages were all mainly coalificated by the plutonic metamorphism. The results show that the same trend as high level in the west and north, low in the east and south. Through analyzing the oil-gas characteristics controlled by coalification, we consider the coalification of the later stage had an important significance to oil-gas exploration because of its later hydrocarbon-generation, greater evolutionary amplitude and deeper hydrocarbon-generation intensity. [Copyright &y& Elsevier]

Abstract: Rapid coal mine gas hydrate formation is the primary key for the application of coal mine gas hydrate technologies such as coal and gas outburst prevention and coal mine gas separation. Gas hydrate formation experiments at initial pressure variations from 7.0 to 9.0 MPa were performed using coal mine gas in the presence of Sodium Dodecyl Sulfate (SDS) in aqueous solution in a high pressure cell. The concentration of SDS in aqueous solution varied from 0.4 to 0.7 mol/L. The kinetic hydrate formation behaviors in the solution were observed. The gas consumption rate and hydrate formation rate were obtained, based on the formation curves of mine gas hydrate, the state equation of real gases and the volume equation of gas hydrate. The hydrate formation rate mainly depends on the initial pressure and SDS concentration. There exists an optimal SDS concentration to maximally promote hydrate growth. [Copyright &y& Elsevier]

Embryonic stem (ES) cells are pluripotent cells with self-renewing property. Nanog is a homeobox transcription factor required to maintain ES cells in a non-differentiated state. Using affinity purification coupled to liquid chromatography-tandem mass spectrometry analysis, we identified Sall4 as a Nanog co-purified protein. Co-immunoprecipitation and glutathione S-transferase pulldown experiments confirmed the interaction between Nanog and Sall4. We showed that Nanog and Sall4 co-occupied Nanog and Sall4 enhancer regions in living ES cells. Knockdown of Nanog or Sall4 by RNA interference led to a reduction in Nanog and Sall4 enhancer activities, providing evidence that these factors are positively regulating these enhancers. Importantly, co-transfection of Sall4 with these ES cell-specific enhancers led to transactivation in heterologous somatic cells. Chromatin immunoprecipitation experiments also showed that Sall4 co-occupied many Nanog binding sites in ES cells. Our data implicate Sall4 as an important component of the transcription regulatory networks in ES cells by cooperating with Nanog. We suggest that Sall4 and Nanog form a regulatory circuit similar to that of Oct4 and Sox2. This study high- lights the extensive regulatory loops connecting genes, which encode for key transcription factors in ES cells. [ABSTRACT FROM AUTHOR]

Abstract: In this paper it is shown that the relationship of bulk modulus with pressure, B=f(P), should be linear both at low and high-pressure limiting conditions. Because most of present equations of state (EOS) for solids cannot satisfy such linear relationship at high pressure, a new function f(P) is proposed to satisfy the linearity. By integrating the bulk modulus, an EOS with three parameters and satisfying the quantum-statistics limitation is derived. It is shown that the EOS can be reduced to two-parameter EOS approximately satisfying the limiting condition. By applying the two EOSs and other three typical EOSs to 50 materials, it is concluded that for materials at low and middle-pressure regimes, the limiting condition does not operate, the Baonza EOS gives the best results, but it cannot provide analytic expression for cohesive energy. The Vinet and our second EOSs are slightly inferior, both EOSs can provide analytic expression for cohesive energy, and for materials at high-pressure regimes our second EOS gives the best results. The Holzapfel and our first EOSs give the worst results, although they strictly satisfy the limiting condition. For practical applications, the limiting condition is not important because it only operates as V→0. [Copyright &y& Elsevier]

RNA G-quadruplexes (rG4s) are noncanonical RNA secondary structures formed by guanine (G)-rich sequences. These complexes play important regulatory roles in both animals and plants through their structural dynamics and are closely related to human diseases and plant growth, development, and adaption. Thus, studying the structural dynamics of rG4s is fundamentally important; however, their folding pathways and their unfolding by specialized helicases are not well understood. In addition, no plant rG4-specialized helicases have been identified. Here, using single-molecule FRET, we experimentally elucidated for the first time the folding pathway and intermediates, including a G-hairpin and G-triplex. In addition, using proteomics screening and microscale thermophoresis, we identified and validated five rG4-specialized helicases in Arabidopsis thaliana. Furthermore, DExH1, the ortholog of the famous human rG4 helicase RHAU/DHX36, stood out for its robust rG4 unwinding ability. Taken together, these results shed light on the structural dynamics of plant rG4s. [ABSTRACT FROM AUTHOR]

A great challenge in developing nanotechnologies for cancer diagnosis and therapy has been the combined functionalities required for complicated clinical procedures. Among all requirements, toxicity has been the major hurdle that has prevented most of the nano-carriers from clinical use. Here, we extracted chlorophyll (Chl) from vegetable and encapsulated it into polymer (pluronic F68, Plu) micelles for cancer imaging and therapy. The results showed that the Chl-containing nanocomposites were capable of mouse tumor targeting, and the nanocomposite fluorescence within the tumor sites remained at high intensity more than two days after tail-vein injection. It is interesting that oral administration with the nanocomposites was also successful for tumor target imaging. Furthermore, the dietary Chl was found to be able to efficiently convert near-infrared laser irradiation to heat. The growths of melanoma cells and mouse tumors were effectively inhibited after being treated with the nanocomposites and irradiation. The suppression of the tumors was achieved by laser-triggered photothermal and photodynamic synergistic effects of Chl. As a natural substance from vegetable, Chl is non-toxic, making it an ideal nano-carrier for cancer diagnosis and treatment. Based on the results of this research, the Plu-Chl nanocomposites have shown promise for future clinical applications. [ABSTRACT FROM AUTHOR]

Purpose: To compare the clinical outcomes of anterior cruciate ligament (ACL) reconstruction with double-bundle and single-bundle techniques. Study design: Meta-analysis Methods: We searched electronic databases including PubMed, Embase, Cochrane Central Register of Controlled Trials, and Google Scholar from1966 to Jan 2012 to identify randomized controlled trials (RCTs) comparing clinical outcomes of anterior cruciate ligament (ACL) reconstruction with double-bundle and single-bundle techniques. Two reviewers independently extracted data and assessed trial quality. Meta-analysis was performed to pool results. Results: Nineteen RCTs were included with a total of 1686 patients. The pooled analysis across all studies showed that the double-bundle ACL reconstruction technique could have significantly better outcomes in rotational laxity, as assessed by the pivot-shift test, KT grading and IKDC grading than the single-bundle techniques. We found no evidence of a difference in function measured by IKDC scores, KT arthrometer, Lysholm knee, or Tegner activity scores and complications after operations between single and double-bundle ACL reconstruction groups. Conclusion: Our meta-analysis demonstrated the superiority of double-bundle over single-bundle anterior cruciate ligament reconstruction. The double-bundle ACL reconstruction technique has better outcomes in rotational laxity (pivot-shift test, KT grading and IKDC grading). However, for functional recovery, there was no significant difference between single-bundle and double-bundle reconstruction techniques. [ABSTRACT FROM AUTHOR]

Tamoxifen-resistant (TAMR) estrogen receptor-positive (ER+) breast cancer is characterized by elevated Erb-B2 receptor tyrosine kinase 2 (ERBB2) expression. However, the underlying mechanisms responsible for the increased ERBB2 expression in the TAMR cells remain poorly understood. Herein, we reported that the ERBB2 expression is regulated at the posttranscriptional level by miR26a/b and the RNA-binding protein human antigen R (HuR), both of which associate with the 3′-UTR of the ERBB2 transcripts. We demonstrated that miR26a/b inhibits the translation of ERBB2 mRNA, whereas HuR enhances the stability of the ERBB2 mRNA. In TAMRER+ breast cancer cells with elevated ERBB2 expression, we observed a decrease in the level of miR26a/b and an increase in the level of HuR. The forced expression of miR26a/b or the depletion of HuR decreased ERBB2 expression in the TAMR cells, resulting in the reversal of tamoxifen resistance. In contrast, the inactivation of miR26a/b or forced expression of HuR decreased tamoxifen responsiveness of the parental ER+ breast cancer cells. We further showed that the increase in HuR expression in the TAMR ER+ breast cancer cells is attributable to an increase in the HuR mRNA isoform with shortened 3′-UTR, which exhibits increased translational activity. This shortening of the HuR mRNA 3′-UTR via alternative polyadenylation (APA) was observed to be dependent on cleavage stimulation factor subunit 2 (CSTF2/CstF-64), which is up-regulated in the TAMR breast cancer cells. Taken together, we have characterized a model in which the interplay between miR26a/b and HuR post-transcriptionally up-regulates ERBB2 expression in TAMR ER+ breast cancer cells. [ABSTRACT FROM AUTHOR]

Objective: In this study, we compared the long-acting hypoglycemic effect of PEGylated FGF21 (PEG-FGF21) with insulin glargine in mice with STZ-induced type 1 diabetes. Methods: PEG-FGF21 and insulin glargine were administered once daily for two months, and blood glucose was measured prior to the next administration. Real-time PCR was used to measure mRNA expression of glucokinase (GK), glucose 6-phosphatase (G6pase), phosphoenolpyruvate carboxykinase (PEPCK), glucose transporter 1 (GLUT1) and glucose transporter 4 (GLUT4). Results: During long-term treatment, the blood glucose of untreated mice remained at 25.0 to 28.0mmol/L for the whole experiment, and the blood glucose of mice treated with insulin glargine remained at 16.5 to 18.0mmol/L. However, mice treated with PEG-FGF21 had lower blood glucose levels of 8.0 to 9.0mmol/L on day 10 and maintained this level until the end of the experiment. qRT-PCR showed that PEG-FGF21 up-regulated mRNA expression of GK and GLUT1, and down-regulated mRNA expression of G6Pase and PEPCK. Insulin glargine up-regulated mRNA expression of GLUT4, but had no effect on GK, G6Pase, PEPCK or GLUT1. Conclusions: PEG-FGF21 has a better long-acting efficacy than insulin glargine. PEG-FGF21 achieves glucose clearance by accelerating glycolysis by up-regulating expression of GK and GLUT1 and inhibiting gluconeogenesis via down-regulation of G6Pase and PEPCK expression. [ABSTRACT FROM AUTHOR]

Complement activation plays a critical role in controlling inflammatory responses. To assess the role of complement during ovarian cancer progression, we crossed two strains of mice with genetic complement deficiencies with transgenic mice that develop epithelial ovarian cancer (TgMISIIR-TAg). TgMISIIR-TAg mice fully or partially deficient for complement factor 3 (C3) (Tg+C3KO and Tg+C3HET, respectively) or fully deficient for complement factor C5a receptor (C5aR) (Tg+C5aRKO) develop either no ovarian tumors or tumors that were small and poorly vascularized compared to wild-type littermates (Tg+C3WT, Tg+C5aRWT). The percentage of tumor infiltrating immune cells in Tg+C3HET tumors compared to Tg+C3WT controls was either similar (macrophages, B cells, myeloid-derived suppressor cells), elevated (effector T cells), or decreased (regulatory T cells). Regardless of these ratios, cytokine production by immune cells taken from Tg+C3HET tumors was reduced on stimulation compared to Tg+C3WT controls. Interestingly, CD31+ endothelial cell (EC) function in angiogenesis was significantly impaired in both C3KO and C5aRKO mice. Further, using the C5aR antagonist PMX53, tube formation of ECs was shown to be C5a-dependent, possibly through interactions with the VEGF165 but not VEGF121 isoform. Finally, the mouse VEGF164 transcript was underexpressed in C3KO livers compare to C3WT livers. Thus, we conclude that complement inhibition blocks tumor outgrowth by altering EC function and VEGF165 expression. [ABSTRACT FROM AUTHOR]