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Taking the upper sub-member of Sha 4 in Well Fanye 1 and Well Niuye 1 in Dongying Sag, Jiyang Depression, Bohai Bay Basin as a typical example, this paper adopts the method of combining macro and micro laminar characterization and complementing each other. The characteristics of laminar development are studied by means of fine description of rock thin sections by cores and electron microscopic observation Reconstruction of the Bohai Bay Basin in sand four period of ancient sedimentary environment, it is concluded that the sand on the four period of development of four complete filling sedimentary cycle. Using Milankovitch cycles method, reveals the ancient climate control mechanism of lithofacies, formed by organic laminae under hot and humid climate and a small amount of calcite laminated lithofacies, in hot and humid climate, the lithofacies is mainly composed of organic lamina and a small amount of calcite lamina, while in cold and dry climate, the lithofacies is mainly composed of calcite lamina, and the lithofacies is mainly composed of organic lamina, silty lamina and gypsum lamina. Micro-laminar research is an important scientific issue in unconventional oil and gas eology. It can provide basic data for unconventional oil and gas exploration, such as the types, distribution and extension of laminar, especially the determination of sampling targets. Different laboratory samples can be analyzed according to the laminar types.

There are remarkable genetic differences between animal major histocompatibility complex (MHC) systems and the human leukocyte antigen (HLA) system. HLA transgenic humanized mouse model systems offer a much better method to study the HLA-A-related principal mechanisms for vaccine development and HLA-A-restricted responses against infection in human.A recombinant gene encoding the chimeric HLA-A30 monochain was constructed. This HHD molecule contains the following: α1-α2 domains of HLA-A30, α3 and cytoplasmic domains of H-2DWe describe a novel human β2m-HLA-A30 (α1α2)-H-2DWe established a promising preclinical research animal model of HLA-A30 Tg humanized mouse, which could accelerate the identification of novel HLA-A30-restricted epitopes and vaccine development, and support the study of HLA-A-restricted responses against infection in humans.

Gliomas are the most common primary intracranial tumor, accounting for more than 70% of brain malignancies. Studies indicate that highly upregulated in liver cancer (HULC), a long noncoding RNA (lncRNA), functions as an oncogene in gliomas. However, the underlying mechanism of HULC in gliomas remains under-studied and was subsequently investigated in the current study. Brain tissues were clinically collected from 50 patients with glioblastoma (GBM) and 35 patients with acute craniocerebral injury, followed by immunohistochemical detection of the expression patterns of Forkhead box M1 (FOXM1), anterior gradient 2 (AGR2), and hypoxia-inducible factor-1α (HIF-1α). After flow cytometry-based sorting of the CD133

Characterization of biomolecular dynamics at cellular membranes lags far behind that in solutions because of challenges to measure transmembrane trafficking with subnanometer precision. Herein, by introducing nonfluorescent quenchers into extracellular environment of live cells, we adopted Förster resonance energy transfer from one donor to multiple quenchers to measure positional changes of biomolecules in plasma membranes. We demonstrated the method by monitoring flip-flops of individual lipids and by capturing transient states of the host defense peptide LL-37 in plasma membranes. The method was also applied to investigate the interaction of the necroptosis-associated protein MLKL with plasma membranes, showing a few distinct depths of MLKL insertion. Our method is especially powerful to quantitate the dynamics of proteins at the cytosolic leaflets of plasma membranes which are usually not accessible by conventional techniques. The method will find wide applications in the systematic analysis of fundamental cellular processes at plasma membranes.

The hexametric T7 helicase (gp4) adopts a spiral lock-washer form and encircles a coil-like DNA (tracking) strand with two nucleotides bound to each subunit. However, the chemo-mechanical coupling mechanism in unwinding has yet to be elucidated. Here, we utilized nanotensioner-enhanced Förster resonance energy transfer with one nucleotide precision to investigate gp4-induced unwinding of DNA that contains an abasic lesion. We observed that the DNA unwinding activity of gp4 is hindered but not completely blocked by abasic lesions. Gp4 moves back and forth repeatedly when it encounters an abasic lesion, whereas it steps back only occasionally when it unwinds normal DNA. We further observed that gp4 translocates on the tracking strand in step sizes of one to four nucleotides. We propose that a hypothetical intermediate conformation of the gp4–DNA complex during DNA unwinding can help explain how gp4 molecules pass lesions, providing insights into the unwinding dynamics of gp4.

Thermodynamics and structural transitions on protein surfaces remain relatively understudied and poorly understood. Wrapping of DNA on proteins provides a paradigm for studying protein surfaces. We used magnetic tweezers to investigate a prototypical DNA-interacting protein, i.e., the single-stranded DNA binding protein (SSB). SSB binds DNA with distinct binding modes the mechanism of which is still elusive. The measured thermodynamic parameters relevant to the SSB-DNA complex are salt-dependent and discontinuous at the bind-mode transitions. Our data indicate that free SSB undergoes salt-induced first-order structural transitions. The conclusion was supported by the infrared spectroscopy of SSB in salt solutions. Ultrafast infrared spectroscopy further suggests that the transitions are correlated with surface salt bridges. Our work not only unravels a long-standing mystery of the different binding site sizes of SSB, but also would inspire interests in thermodynamics of protein surfaces.

It is a big challenge to measure position changes of biomolecules in the direction normal to the plasma membranes of living cells. We developed a one donor-multiple quenchers Fӧrster resonance energy transfer method by using non-fluorescent quenchers in the extracellular environment. It senses subnanometer position changes of a fluorophore-labeled biomolecule in the plasma membrane. The method was validated by monitoring flip-flops of individual lipid molecules incorporated in plasma membranes. We studies membrane perforation by a host defense peptide from the extracellular side and found that the pore-forming peptide is dynamic, switching among different insertion depths. The method is especially useful in studying interactions of membrane proteins with the inner surfaces of plasma membranes. Our method will find wide applications in systematic analysis of fundamental cellular processes at plasma membranes.

For the current shared problem of multi inverters connected the grid in the micro-grid, the virtual reactance is introduced to solve the strong coupled problem between active power and reactive power when the line shows resistive characteristic, so the distribution of power among inverters can be achieved by conventional power droop control. Then the reference voltage obtained by power droop control has been transformed into reference current for controlled objective. Considering that the parameters of multi inverters connected the grid are unknown precisely or time-varying slowly, a kind of adjustable PID controller based on adaptive internal model is designed, and high precise current control is achieved. The simulation results show that good steady and dynamic performance can be obtained by the proposed control scheme.

Tracking membrane-interacting molecules and visualizing their conformational dynamics are key to understanding their functions. It is, however, challenging to accurately probe the positions of a molecule relative to a membrane. Herein, a single-molecule method, termed LipoFRET, is reported to assess interplay between molecules and liposomes. It takes advantage of FRET between a single fluorophore attached to a biomolecule and many quenchers in a liposome. This method was used to characterize interactions between α-synuclein (α-syn) and membranes. These results revealed that the N-terminus of α-syn inserts into the membrane and spontaneously transitions between different depths. In contrast, the C-terminal tail of α-syn is regulated by calcium ions and floats in solution in two conformations. LipoFRET is a powerful tool to investigate membrane-interacting biomolecules with sub-nanometer precision at the single-molecule level.

microRNAs (miRNAs) have been found to affect various cancers, and expression of numerous miRNAs is revealed in glioma. However, the role of microRNA-30b-3p (miR-30b-3p) in glioma remains elusive. Therefore, the present study aims to explore the specific mechanism by which miR-30b-3p influence the development of glioma in relation to the AKT signaling pathway. First, glioma cell lines were collected with miR-30b-3p and reversion-inducing cysteine-rich protein with kazal motifs (RECK) expression measured. The functional role of miR-30b-3p and RECK in glioma was determined via gain- and loss-of-function approaches. Subsequently, the expression of invasion- and migration-related factors (MMP-2 and MMP-9) and the AKT signaling pathway-related factors (AKT, p-AKT and PI3K-p85) was detected. Moreover, in vivo experiments were also conducted to investigate how miR-30b-3p influences in vivo tumorigenesis. The results showed that miR-30b-3p was up-regulated and RECK was down-regulated in glioma. RECK was a target gene of miR-30b-3p. Decreased miR-30b-3p and overexpressed RECK led to decreased expression of MMP-2, MMP-9 and p-AKT. Overexpressed RECK and LY294002 could decrease p-AKT and PI3K-p85 expression accompanied with unchanged expression of total protein of AKT. Additionally, proliferation, migration and invasion of glioma cells and tumor formation in nude mice were repressed owing to reduced expression of miR-30b-3p or elevated expression of RECK. In summary, miR-30b-3p inhibition suppresses metastasis of glioma cells by inactivating the AKT signaling pathway via RECK up-regulation, providing a new target for glioma treatment.

The aim of this study was to assess the clinical value of radial probe endobronchial ultrasound (RP-EBUS)-guided localization of solitary pulmonary nodules (SPNs) with the combination of ultrathin bronchoscopy and methylene blue prior to video-assisted thoracoscopic surgery (VATS). An ultrathin bronchoscope was used to localize the lesions under RP-EBUS guidance in 48 patients (18 men and 30 women; age range, 41–72 years; mean age, 54 years), who subsequently underwent VATS resection. The lesion size, distance from the parietal pleura, localization time and complications were evaluated. The RP-EBUS-guided localization success rate was 72.9%. The lesion size ± standard deviation was 12.8±4.2 mm and the mean distance from the parietal pleura was 11.2±9.7 mm. The mean localization time was 15.7±8.3 min. The major complication of RP-EBUS-guided localization was asymptomatic hemorrhage in 4 patients (8.3%). The VATS resection success rate was 95.8%. In terms of pathological type, the 48 lesions included atypical adenomatous hyperplasia (n=4), adenocarcinoma in situ (n=5), minimally invasive adenocarcinoma (n=7), adenocarcinoma (n=18), squamous cell carcinoma (n=1), inflammation (n=6), hamartoma (n=4) and tuberculosis (n=3). Therefore, RP-EBUS-guided localization with the combination of an ultrathin bronchoscope and methylene blue prior to VATS resection is a promising technique for SPNs, it plays an important role in the accurate localization of SPNs and it is an effective and safe technique to assist VATS resection of such nodules.

Many studies have suggested that folate-related one-carbon metabolism-related nutrients may play a role in certain cancer risks, but few studies have assessed their associations with the risk for nasopharyngeal carcinoma (NPC). In this study, we investigated the association between four folate-related one-carbon metabolism-related nutrients (folate, vitamin B6, vitamin B12 and methionine) and NPC risk in Chinese adults. A total of 600 patients newly diagnosed (within 3 months) with NPC were individually matched with 600 hospital-based controls by age, sex and household type (urban v. rural). Folate, vitamin B6, vitamin B12 and methionine intakes were measured using a validated seventy-eight-item FFQ. A higher dietary folate or vitamin B6 intake was associated with a lower NPC risk after adjusting for potential confounders. The adjusted OR of NPC for quartiles 2–4 (v. 1) were 0·66 (95 % CI 0·48, 0·91), 0·52 (95 % CI 0·37, 0·74) and 0·34 (95 % CI 0·23, 0·50) (PtrendPtrend6. No significant association with NPC risk was observed for dietary vitamin B12 or methionine intake. The risk for NPC with dietary folate intake was more evident in the participants who were not exposed to toxic substances than in those who were exposed (Pinteraction=0·014). This study suggests that dietary folate and vitamin B6 may be protective for NPC in a high-risk population.

Homologous recombination (HR) which is important for maintaining the genetic stability of the cell is mainly mediated by recombinase. As a critical recombinase exists in prokaryotic organism, RecA has been widely studied. RecA could bind single strand DNA to form a filament structure to perform strand invasion and exchange with homologous DNA. The basic strand exchange step is a pathway to investigating the mechanism of strand exchange process. However, the specific step length is still controversial. The mainstream view is to regard the basic step as 3 bp, which sounds reasonable because the basic unit of RecA filament is a RecA monomer which binds 3 base pairs, but our previous study found that the most probable basic strand exchange step is 9 bp. In this research, we set up a series of experiments to demonstrate that the basic strand exchange step is 9 bp and how the mismatch base pairs in 9 bp affect the strand exchange process. We ues digestion protection to confirm whether the strand exchange process is completed and we employ a magnetic tweezer to measure how many base pairs are exchanged by strand exchange process. The digestion protection experiments show the strand exchange cannot overcome 33% mismatch sequence, but according to the result that strand exchange could overcome a single mismatch base pair, so that the step is not 3 bp. According to strand exchange length of 33% mismatch sequence, we find a 9 bp interval between the main peaks, which implies that the strand exchange step should be 9 bp rather than 3 bp. We also use continuous mismatch base pairs instead of periodic mismatch sequence to see whether the strand exchange process can be overcome. We find that the more the mismatch base pairs, the harder the strand exchange process passes across. Homology degree and its distribution both affect the strand exchange process. In general, the results suggest that the strand exchange step mediated by RecA is 9 bp, and the number of mismatched base pairs and their distribution influence the strand exchange process. The combination of digestion protection assay and magnetic tweezers can further take advantage of single molecule techniques to investigate mechanism of HR.

Helicases harness the energy of nucleotide triphosphate hydrolysis to unwind double-stranded DNA (dsDNA) in discrete steps. In spite of intensive studies, the mechanism of stepping is still poorly understood. Here, we applied single-molecule fluorescent resonant energy transfer to characterize the stepping of two nonring helicases, Escherichia coli RecQ ( E. coli RecQ) and Saccharomyces cerevisiae Pif1 (ScPif1). Our data showed that when forked dsDNA with free overhangs are used as substrates, both E. coli RecQ and ScPif1 unwind the dsDNA in nonuniform steps that distribute over broad ranges. When tension is exerted on the overhangs, the overall profile of the step-size distribution of ScPif1 is narrowed, whereas that of E. coli RecQ remains unchanged. Moreover, the measured step sizes of the both helicases concentrate on integral multiples of a half base pair. We propose a universal stepping mechanism, in which a helicase breaks one base pair at a time and sequesters the nascent nucleotides and then releases them after a random number of base-pair breaking events. The mechanism can interpret the observed unwinding patterns quantitatively and provides a general view of the helicase activity.

There are lines of evidence that the Bloom syndrome helicase, BLM, catalyzes regression of stalled replication forks and disrupts displacement loops (D-loops) formed during homologous recombination (HR). Here we constructed a forked DNA with a 3' single-stranded gap and a 5' double-stranded handle to partly mimic a stalled DNA fork and used magnetic tweezers to study BLM-catalyzed unwinding of the forked DNA. We have directly observed that the BLM helicase may slide on the opposite strand for some distance after duplex unwinding at different forces. For DNA construct with a long hairpin, progressive unwinding of the hairpin is frequently interrupted by strand switching and backward sliding of the enzyme. Quantitative study of the uninterrupted unwinding length (time) has revealed a two-state-transition mechanism for strand-switching during the unwinding process. Mutational studies revealed that the RQC domain plays an important role in stabilizing the helicase/DNA interaction during both DNA unwinding and backward sliding of BLM. Especially, Lys1125 in the RQC domain, a highly conserved amino acid among RecQ helicases, may be involved in the backward sliding activity. We have also directly observed the in vitro pathway that BLM disrupts the mimic stalled replication fork. These results may shed new light on the mechanisms for BLM in DNA repair and homologous recombination.

The fault mathematic model of the transmission part of wind energy conversion system (WECS) is established, and adaptive fault observer is constructed in the presence of unknown disturbance, it can detect the faults of the system, and estimate these faults. Then, based on fault observer, an active tolerant controller is designed to ensure the stability of the transmission part of WECS with fault.The simulation results of different type faults of generator show the effectiveness and feasibility of adaptive fault diagnosis methods.

The present work aims to investigate bromate removal from water with the application of a material nano Fe 0 /OMC (ordered mesoporous carbon) composite, under various experimental conditions. The effect of temperature, react time, bromate concentration, etc . on bromate removal efficiency was studied. Removal efficiency of bromate by nano Fe 0 /OMC achieved 96.1% with a contact time of 10 min at 298 K. Reduction action dominates the whole process with a little adsorption accompanied, and approximately 90% bromate was restored to bromide. Kinetics models were used to correlate the kinetics experimental data and the kinetics parameters reveal that the kinetics data were well fitted to pseudo-second-order model. The maximum bromate uptake at 298 K was found to be 25.9 mg/g at the initial bromate concentration 10 mg/L, but it changed little with a decrease in temperature. Equilibrium isotherms were analyzed by the Freundlich and Langmuir isotherm models. The data fit favorable to the Langmuir isotherms with high-correlation coefficients (0.941–0.998). The present work shows that the nano Fe 0 /OMC composite would be a promising material in the study of drinking water purification.

Single-molecule F\"orster resonance energy transfer is widely applied to study helicases by detecting distance changes between a pair of dyes anchored to overhangs of a forked DNA. However, it has been lacking single-base pair (1-bp) resolution required for revealing stepping kinetics of helicases. We designed a nanotensioner in which a short DNA is bent to exert force on the overhangs, just as in optical or magnetic tweezers. The strategy improved the resolution of F\"orster resonance energy transfer to 0.5 bp, high enough to uncover differences in DNA unwinding by yeast Pif1 and E. coli RecQ whose unwinding behaviors cannot be differentiated by currently practiced methods. We found that Pif1 exhibits 1-bp-stepping kinetics, while RecQ breaks 1 bp at a time but sequesters the nascent nucleotides and releases them randomly. The high-resolution data allowed us to propose a three-parameter model to quantitatively interpret the apparently different unwinding behaviors of the two helicases which belong to two superfamilies.

In order to further improve the baking energy recovery rate of extended-range electric vehicle (E-REV), thus to extend driving distance, a high efficiency regenerative braking control strategy for E-REV was proposed. Based on the co-simulation platform with AVL-Cruise and Simulink, a dynamic model for E-REV was set up and simulation calculations on hybrid motor-mechanical regenerative braking were performed. The simulation results with typical driving cycles illustrate that the friction braking force and the regenerative braking force could be well integrated, braking energy recovery efficiency was high, and the proposed control strategy of regenerative braking in the paper is effective.

For the single phase inductance-capacitance-inductance (LCL) grid-connected inverter in micro-grid, a kind of robust iterative learning controller is designed. Based on the output power droop characteristics of inverter, the current sharing among the inverters is achieved. Iterative learning strategy is suitable for repeated tracking control and inhibiting periodic disturbance, and is designed using robust performance index, so that it has the ability to overcome the uncertainty of system parameters. Compared with the repetitive control, the robust iterative learning control can get high precision output waveform, and enhance the tracking ability for waveform, and the distortion problem of the output signal can be solved effectively.

The basic configuration and operation modes of the series extended-range electric vehicle were analyzed and a new method of engine choice and fuel economy evaluation was proposed. A co-simulation platform is set up with Cruise and Matlab/Simulink to evaluate the rule-based engine on-off and optimal operation line control strategies. The simulation results with typical driving cycles illustrate that: firstly, the engine on-off control strategy makes engine and generator operate on their best efficiency points, and its fuel economy is better than optimal operation line control strategy; secondly, when the optimal operation line control strategy is adopted in Extended-Range Mode, the engine downsizing will be beneficial and the extended-range electric vehicle (E-REV) will achieve a better fuel economy and control effect.

Human Cripto-1 (CR-1) plays an important oncogenic role during tumorigenesis and is overexpressed in a wide range of carcinomas, yet little is known about CR-1 in non-small cell lung cancer (NSCLC). The aims of this study were to detect CR-1 expression in NSCLC and to analyze its association with prognosis of NSCLC patients. The expression of CR-1 messenger RNA (mRNA) and protein in 35 cases of NSCLC and corresponding noncancerous tissue samples was examined by quantitative real-time reverse transcription–polymerase chain reaction (qRT–PCR) and Western blotting. Immunohistochemistry was performed to detect the expression of CR-1 in 128 NSCLC tissues. The expression levels of CR-1 mRNA and protein in NSCLC tissues were significantly higher than those in corresponding noncancerous tissues (P

The aim of this study was to explore the diagnostic and prognostic value of serum human kallikrein-related peptidases 11 (KLK11) level in non-small cell lung cancer (NSCLC). Serum specimens from 138 patients with NSCLC and 40 healthy controls were collected. The concentration of KLK11 was measured by enzyme-linked immunosorbent assay (ELISA). The concentration of KLK11 in NSCLC was significantly higher compared to that in the controls (P

Background: Intakes of choline and betaine have been inversely related to the risk of various neoplasms, but scant data exist on nasopharyngeal carcinoma (NPC). We examined the association between consumption of choline and betaine and risk of NPC. Methods: We conducted a case–control study with 600 incident NPC patients and 600 controls 1 : 1 matched by age, sex and household type in Guangdong, China. Dietary intake was assessed by a food frequency questionnaire through face-to-face interview. Results: Intakes of total choline, betaine and choline+betaine were inversely related to NPC after adjustment for various lifestyle and dietary factors (all P-trend

Aiming at the problems presented in the design of large-size vessels, structure optimization of the pressure vessel with large opening and reinforcement is mainly discussed. Firstly, 3D finite element model was established for the pressure vessel with large opening. Then, the local equivalent stress of the vessel with large opening in the thermal stress coupled field is analyzed based on ANSYS software. Secondly, taking the wall thickness of tank body and connecting pipe, the width and thickness of reinforcement pad as design variables, allowable stress as constrain condition, different structure schemes were proposed. Finally, the optimal scheme was determined through analyzing and comparing different schemes.

In order to solve the problems existed in gearshift with wet dual clutch transmission; the down-shift control strategy is developed on the basis of analysis on gear shift process. Clutch pressure intelligent control arithmetic based on FCMAC (Fuzzy Cerebellar Model Articulation Controller) is designed to realize accuracy control of clutch pressure. The transmission control unit is designed, and the control program is written. Taking down-shift from 2 to 1 for example, down-shifting control strategy was drawn. After applied the introduced method into the experiments on both power-on and power-off downshift under different throttle positions, ideal shifting quality was achieved. The result indicated that the speed of vehicle changed gently without distinct impact. This essay verifies the validity of the proposed method of the strategy of shifting control.

The aim of this study was to explore the diagnostic value of levels of the serum-soluble receptor-binding cancer antigen expressed on SiSo cells (sRCAS1) expressed in lung cancer patients. Enzyme-linked immunosorbent assay was performed to detect serum sRCAS1 levels in 138 patients with lung cancers of various types and in 40 healthy controls. Our results showed that the patients with lung cancer had higher serum sRCAS1 levels than the controls. As disease stages progressed in lung cancer, serum sRCAS1 levels increased; patients with lymph node and distant metastases had higher levels than those without metastases, regardless of histology, age, and gender. At a cutoff value of 19.2 U/ml, sRCAS1 was 91.3 % sensitive and 72.5 % specific for lung cancer. In conclusion, these results suggest that sRCAS1 levels could have a clinical value for the diagnosis and management of lung cancer and could be used as a new tumor marker of lung cancer.

In this work, plasma combined with maleic anhydride induced-graft polymerization method was employed to fabricate highly-functionalized carbon nanotubes, whose surface was coated by uniform polymaleic anhydride thin film. Their compositions and structures were characterized by FTIR, SEM and XPS techniques. In order to evaluate the modification effect, they were further used as modifier to improve the tensile and surface properties of fluorinated polyurethane elastomers.

The motivation for this development is to establish a new method of powertrain structural analysis and parameters matching of extended-range electric vehicle. For the main drawback of pure electric vehicle, which driving distance is short, the new powertrain will achieve efficient operation of range extender and extend the driving range effectually. The innovative technique is based on a co-simulation platform of AVL-Cruise and Simulink. A thermostat energy management strategy is adopted to verify the parameters of powertrain. Finally, the simulation results demonstrate that the system design and parameters matching of the whole vehicle powertrain are reasonable.

Research on the dynamics of single-membrane proteins remains underdeveloped due to the lack of proper approaches that can probe in real time the protein's insertion depth in lipid bilayers. Here we report a single-molecule visualization method to track both vertical insertion and lateral diffusion of membrane proteins in supported lipid bilayers by exploiting the surface-induced fluorescence attenuation (SIFA) of fluorophores. The attenuation follows a d−4 dependency, where d is the fluorophore-to-surface distance. The method is validated by observing the antimicrobial peptide LL-37 to transfer among five transmembrane positions: the surface, the upper leaflet, the centre, the lower leaflet and the bottom of the lipid bilayer. These results demonstrate the power of SIFA to study protein-membrane interactions and provide unprecedented in-depth understanding of molecular mechanisms of the insertion and translocation of membrane proteins., Assessing protein localization within lipid membranes is problematic. Here, the authors describe a single molecule visualization method based on surface-induced fluorescence attenuation (SIFA) to determine the insertion depth and lateral diffusion of a peptide in a lipid bilayer.

Recombinase-mediated homologous recombination (HR) in which strands are exchanged between two similar or identical DNA molecules is essential for maintaining genome fidelity and generating genetic diversity. It is believed that HR comprises two distinct stages: an initial alignment with stringent homology checking followed by stepwise heteroduplex expansion. If and how homology checking takes place during heteroduplex expansion, however, remains unknown. In addition, the number of base pairs (bp) involved in each step is still under debate. By using single-molecule approaches to catch transient intermediates in RecA-mediated HR with different degrees of homology, we show that (i) the expansion proceeds with step sizes of multiples of 3 bp, (ii) the step sizes follow wide distributions that are similar to that of initial alignment lengths, and (iii) each distribution can be divided into a short-scale and a long-scale part irrespective of the degree of homology. Our results suggest an iterative mechanism of strand exchange in which ssDNA-RecA filament interrogates double-stranded DNA using a short tract (6–15 bp) for quick checking and a long tract (>18 bp) for stringent sequence comparison. The present work provides novel insights into the physical and structural bases of DNA recombination.

Pif1 is a prototypical member of the 5' to 3' DNA helicase family conserved from bacteria to human. It has a high binding affinity for DNA, but unwinds double-stranded DNA (dsDNA) with a low processivity. Efficient DNA unwinding has been observed only at high protein concentrations that favor dimerization of Pif1. In this research, we used single-molecule fluorescence resonance energy transfer (smFRET) and magnetic tweezers (MT) to study the DNA unwinding activity of Saccharomyces cerevisiae Pif1 (Pif1) under different forces exerted on the tails of a forked dsDNA. We found that Pif1 can unwind the forked DNA repetitively for many unwinding-rezipping cycles at zero force. However, Pif1 was found to have a very limited processivity in each cycle because it loosened its strong association with the tracking strand readily, which explains why Pif1 cannot be observed to unwind DNA efficiently in bulk assays at low protein concentrations. The force enhanced the unwinding rate and the total unwinding length of Pif1 significantly. With a force of 9 pN, the rate and length were enhanced by more than 3- and 20-fold, respectively. Our results imply that the DNA unwinding activity of Pif1 can be regulated by force. The relevance of this characteristic of Pif1 to its cellular functions is discussed.

B7-H4, a member of the inhibitory B7 family, can restrain T cell proliferation, activation, cytokine secretion, and may be involved in immune evasion in cancer patients.This aim of the study was to determine the expression level of soluble B7-H4 (sB7-H4) in circulation and to subsequently evaluate the clinical significance of circulating sB7-H4 in patients with non-small cell lung cancer (NSCLC).Serum specimens from 128 patients with NSCLC, 100 healthy volunteers (HV), and 80 patients with benign lung diseases (BLD) were collected. The concentrations of sB7-H4 were measured by sandwich enzyme-linked immunosorbent assay.Serum sB7-H4 levels in patients with NSCLC were significantly higher than those in patients with BLD (P 0.05), or those in HV (P 0.05). Using a cutoff of 27.8 ng/mL, the sensitivity and specificity of sB7-H4 in differentiating between patients with NSCLC and patients with BLD, and between patients with NSCLC and HV was, 46.9% and 92.5%, and 54.7% and 95.0%, respectively. An area under the curve (AUC) for NSCLC resulting from sB7-H4 (0.863), which was significantly better than any other tumour markers tested including CA125 (0.763), and CEA (0.775).In conclusion, assessment of serum sB7-H4 levels could be considered as a diagnostic biomarker for NSCLC.

Many studies show that dietary factors may affect the risk of nasopharyngeal carcinoma (NPC). We examined the association between overall diet quality and NPC risk in a Chinese population. This case-control study included 600 NPC patients and 600 matched controls between 2009 and 2011 in Guangzhou, China. Habitual dietary intake and various covariates were assessed via face-to-face interviews. Diet quality scores were calculated according to the Healthy Eating Index-2005 (HEI-2005), the alternate Healthy Eating Index (aHEI), the Diet Quality Index-International (DQI-I), and the alternate Mediterranean Diet Score (aMed). After adjustment for various lifestyle and dietary factors, greater diet quality scores on the HEI-2005, aHEI, and DQI-I—but not on the aMed—showed a significant association with a lower risk of NPC (p-trends

The effect of fruit and vegetable intake on the risk of nasopharyngeal carcinoma (NPC) remains uncertain due to limited published evidence. We performed a matched case-control study to investigate the relationship between the intake of fruit and vegetables and the risk of NPC.Between July 2009 and March 2011, 600 (448 male, 152 female), NPC incident cases from a single hospital in Guangzhou, Guangdong Province, China, a high-incidence area, were enrolled in the study. 600 controls, matched by gender, age (± 3 years) and household type (urban/rural) were also enrolled. Face-to-face interviews were used to collect habitual dietary intakes and information on various covariates.Multivariate conditional logistic regression analyses showed significant, dose-dependent inverse associations between the intake of vegetables, fruit or a combination of the two and the risk of NPC, even after adjustments for social-economic status, body mass index, dietary factors and other potential covariates. The adjusted odds ratios (95% confidence intervals) for NPC in the top quartile of vegetable intake, fruit intake or a combination of the two, as compared to the lowest quartile, were 0.33 (0.22-0.50), 0.70 (0.47-1.04) and 0.37 (0.25-0.55), respectively. Dark green leafy vegetables, carrots, peppers and tomatoes, citrus fruit and pome fruit showed much more pronounced benefits with regards to NPC than other types of fruit and vegetables. Interaction analyses demonstrated that the effects of total combined vegetable and fruit intake were much more significant in subjects with a higher education level (p interaction: 0.027), and the benefits of fruit were observed in males, but not in females (p interaction: 0.088).Our findings suggest that a greater consumption of fruit and vegetables may lower the risk of NPC in Chinese adults.

The influence of Ga and Bi on the microstructure and electrochemical performance of Al-7Zn-0.1Sn (mass fraction, %) sacrificial anodes was investigated by means of optical microscopy (OM), scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDAX) and electrochemical measurements. It was found that the coarse dendrites structure transformed into the equiaxed grains as well as a small amount of dendrite grains after adding Ga and Bi into Al-Zn-Sn alloys. A high current efficiency of 97% and even corrosion morphology were obtained for Al-7Zn-0.1Sn-0.015Ga-0.1Bi alloy. The results indicate that the proper amount of Ga and Bi is effective on improving the microstructure and electrochemical performance of Al-Zn-Sn alloy.

TiO2nanotube arrays were fabricated in the electrolyte containing 0.25wt% NH4F, 2.5vol% water and the ethylene glycol for various hours at room temperature by anodization of Ti foil in this paper. Some anodized specimens were annealed at 450°C for 3 hours. Electrochemical Impedance Spectroscopy (EIS) was employed to measure electrochemical parameters of anodized specimens. The morphology and crystalline structure of anodized products were characterized by Field Emission Scanning Electronic Microscopy (FESEM), X-ray Diffraction (XRD) and Transmission Electronic Microscopy (TEM). A non-tube layer appears on nanotube arrays with the increase in anodization time. Anodized TiO2nanotube arrays have an amorphous structure, which transfers to anatase structure after annealing at 450°C. A new equivalent circuit R(CR(R(QR)(CR))) was proposed to fit EIS data. The results show that the charge transfer resistance at the electrode/electrolyte interface controls the electrochemical process of TiO2nanotubes.

Because of the change of using function of one masonry structure, its longitudinal walls need to be underpinned. The related members also need to be reinforced. This paper has a discussion on the thought of underpinning part, strengthening method and key construction process. They main involve the reinforcement of foundation, the transformation from non-bearing members to bearing members of ring beams and constructional columns. It also involves the construction points for attention during underpinning process. At last, the main points that shuold be paid attention to in strengthening deign and underpinning construction are concluded.

After a long period time of working, an auxiliary shaft RC headframe in a colliery got series quality problems, such as the concrete carbonation of the RC members, the concrete loosen and spalling, the exposed steel bar, steel corrosion and the degradation of the bond quality. After making a detailed operating environment and safety detection and evaluation, we studied the deterioration mechanism and the rehabilitation and strengthening technology. Considering that the headframe belongs to the special structures of colliery, we emphatically introduced the strengthening design method and process in order to provide the similar reinforcement project with a reference.

Three newly recorded species of the genus Pardosa from China are described: P. bukukun Logunov & Marusik, 1994, P. graminea Tanaka, 1985 and P. lugubris (Walckenaer, 1802)