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// Hongyun Chen 1 , Shuang Liu 2 , Zhihong Zong 3 , Cuiting Zhao 2 , Guangyuan Li 2 , Yonghuai Wang 2 , Guoxian Qi 1 , Jun Yang 2 and Chunyan Ma 2 1 Department of Geriatric Cardiology, First Hospital of China Medical University, Shenyang, Liaoning, China 2 Department of Cardiovascular Ultrasound, First Hospital of China Medical University, Shenyang, Liaoning, China 3 China Medical University, Shenyang, Liaoning, China Correspondence to: Chunyan Ma, email: cmu1h_mcy@126.com Keywords: cardiac resynchronization therapy (CRT); SERCA2A; endo-CRT; epi-CRT; dyssynchronous heart failure Received: March 29, 2017 Accepted: December 29, 2017 Published: January 02, 2018 ABSTRACT The aims of the present study were to compare the effects of endocardial cardiac resynchronization therapy (endo-CRT) and epicardial CRT (epi-CRT) on cardiac contractile function and to delineate the underlying molecular mechanisms. Twenty-four adult mongrel canines were divided into four groups: sham-operation control group (CT, n = 6), dyssynchronous heart failure (DHF) group ( n = 6), epi-CRT group ( n = 6), and endo-CRT group ( n = 6). The global and local left ventricle (LV) systolic function, dyssynchrony and myocardium calcium handling molecular mRNA and protein levels were measured. Compared to CT group, we found the global and local LV function, dyssynchrony and SERCA2A decreased in DHF group and increased in CRT groups, particularly in endo-CRT group at LV lateral wall (pacing site). Therefore, endo-CRT appears to be an effective procedure in the treatment of DHF, which might be mediated by upregulating the mRNA and protein expression of SERCA2A in the LV at the pacing and remote site.

The evolution of the provenance of aeolian deposits on the Chinese Loess Plateau (CLP) is closely linked to changes in source aridity and dust transport dynamics. Although previous studies have revealed that the provenance of Chinese aeolian deposits may have fluctuated on tectonic timescales, the exact timing and cause of the provenance shifts remain poorly constrained due to limitations of the isotopic and mineralogical tracers used. Here we report the results of electron spin resonance (ESR) signal intensity and crystallinity index (CI) of fine-grained (

We propose a scheme for nonreciprocal light propagation in two coupled cavities system, in which a two-level quantum emitter is coupled to one of the optical microcavities. For the case of parity-time ($${\mathscr{P}}{\mathscr{T}}$$ P T ) symmetric system (i.e., coupled active-passive cavities system), the cavity gain can significantly enhance the optical nonlinearity induced by the interaction between a quantum emitter and cavity field beyond weak-excitation approximation. The increased optical nonlinearity results in the non-lossy nonreciprocal light propagation with high isolation ratio in proper parameters range. In addition, our calculations show that nonreciprocal light propagation will not be affected by the unstable output field intensity caused by optical bistability, and we can even switch directions of nonreciprocal light propagation by appropriately adjusting the system parameters.

We present a systematic investigation of the oxygen isotopic composition of quartz in both fine and coarse fractions ( 18 O values of both the fine and coarse fractions from the various sources are overlapped to varying degrees, thus making it difficult to differentiate them. Nevertheless, the quartz δ 18 O values of both fractions exhibit an increasing trend from the Mongolian Gobi, to the northern Chinese deserts, and then to the Taklimakan desert. This implies that the geological settings of the source areas are different, which in turn results in differing contributions of high-temperature igneous rocks. The combination of quartz δ 18 O results with other quartz-based provenance tracers can clearly differentiate the three major source areas, i.e., the Taklimakan desert, the Mongolian Gobi, and the northern Chinese deserts. In addition, comparison of our results with previous δ 18 O measurements of fine-grained quartz from the Luochuan loess sequence suggests the likely glacial–interglacial fluctuations in dust provenance. Finally, we suggest that the combination of quartz δ 18 O signatures and other dust provenance tracers can potentially improve the recognition of long-term fluctuations in the provenance of Chinese loess-red clay deposits.

Faithfully tracing sources of sediment and then quantifying the flux of each source are the first-order basis for reconstructing paleoclimate and paleoenvironment using lake sediments. The budget of various sources contributing to lake sediment in Lake Qinghai, the largest lake on the Tibetan Plateau, is controversial. In the previous study, the flux of the dust deposition to the modern lake sediment was obtained through 2-year observations, but estimations of other sources have some uncertainties due to inadequate data. In this study our new estimations for the modern Lake Qinghai sediment using new measured data show (1) that contribution (22.1 ± 5.2 %) of the fluvial particulate matter is of second significance, only about one-third of the dust deposition, to the modern lake sediment, when its quick deposition near river mouths is not considered, (2) that lacustrine organisms contribute only 5.2 ± 1.1 % of the sediment, but account for ~70 % of the organic matter in sediment, and (3) that authigenic carbonates contribute 21.0 ± 8.6 % of the sediment and 63.6 % of the total carbonates in the lake sediment, respectively, which is due to a direct precipitation of both Ca2+ and Mg2+ in the modern Ca2+-limited lake. These quantifications are instructive to understand the particulate fluxes to sediment pools in Lake Qinghai under the present conditions and to reconstruct paleoclimate and paleoenvironment via physical and geochemical proxies using past sediments.

The purpose of this study is to evaluate the safety performance of four exit ramp types and the major contributing factors on motorcycle crashes and injury severity of motorcycle riders. A six-year crash data were collected in Florida, and a web-based survey (234 samples) was conducted. 573 crashes were found at 419 exits, including 178 diamond exits, 71 directional exits, 85 loop exits and 85 outer connection exits. For a diamond exit, both the survey and crash data showed that this type was safer and more preferable by motorcycle riders; while a loop exit was the most dangerous exit due to the sharp curve and a certain length of curve with limited visibility. For a directional exit, longer ramp lengths and the reverse curvature are the major factors causing motorcycle crashes. For an outer connection exit, the riders rated it as a safe type; however, the data showed higher average crash frequency and rate than those at diamond exits or directional exits. The possible reason could be the unexpected curvature in the middle of the ramp, which could be dangerous if the rider is not familiar with the exit ramp location or doesn’t pay attention to the ramp curvatures. The crash predictive model was developed, and the result indicated that if all remained the same, a directional exit, a loop exit, or an outer connection exit will have 16%, 27%, and 42% more crashes than a diamond exit, respectively. The findings from this study can help policy-makers and engineers to develop and apply effective countermeasures to reduce motorcycle crashes and injury severity levels for different exit ramp types.

A coupled active-passive double-cavity system with balanced effective gain and loss provides a powerful platform for sideband generation. In different-input limit, we explore the gain-saturation nonlinearity of the active cavity carefully in sideband generation. Through perturbation method, we give an explicit analytical expression of second-order sideband generation (SSG) not only with over 80% conversion efficiency, but also with the pump power as low as ~ µW. A remarkable mode-splitting is also observed during the SSG process in the unbroken parity-time (PT) symmetry phase. Changing the system parameters largely, our numerical method shows that high-order sideband generation (HSG) in the unbroken PT phase is controllable, including increasing its amplitudes and changing its order numbers, especially switching HSG between perturbative- and nonperturbative-regime. In the broken PT phase, the field localization effect leads to the stronger output spectra intensity than in the unbroken PT phase.

Thermal interface materials with high thermal conductivity are essential to transfer the redundant heat and improve the reliability of integrated circuits. Here we reported high thermal conductivity in polydimethylsiloxane (PDMS) nanocomposite incorporated with few-layer graphene, which was exfoliated in chloroform with assistance of hyperbranched polyethylene-g-polyhedral oligomeric silsesquioxane copolymer (HBPE@POSS) as the stabilizer. In order to improve the compatibility and enhance the thermal property, the HBPE@POSS copolymer was synthesized via the unique chain walking polymerization mechanism, which subsequently was applied to exfoliate natural graphite into few-layer graphene in low-boiling-point solvents. The majority of resultant nanosheets with low defects was verified with lateral dimension of ~400 nm and the thickness of ~1.6 nm, which is attributed to the presence of CH-π noncovalent interaction between graphene and HBPE@POSS copolymer. The graphene nanoplates (GNPs)/polydimethylsiloxane (PDMS) nanocomposites were prepared by solution casting, in which graphene nanofillers were dispersed uniformly in the matrix due to good compatibility between PDMS and oligomeric silsesquioxane segments adsorbed on the nanosheets. The thermal conductivity of 4.0 wt% GNPs/PDMS nanocomposite reaches 0.93 W m-1 K-1, which is 400% higher than that of pure PDMS. The PDMS nanocomposite incorporated with few-layer graphene exhibits a promising prospect in thermal interface for thermal management of electronic devices, and sheds a light on the interfacial improvement mechanism of thermal conductivity for polymer composite.

[1] Electron spin resonance (ESR) signal intensity and crystallinity index (CI) of fine- ( 16 µm) quartz were measured in surface samples from the Taklimakan desert in western China, the Badain Juran, Tengger and Mu Us deserts in northern China, and the Gobi desert in southern Mongolia to evaluate whether these geophysical parameters can serve as reliable provenance tracers of Asian dust. The results indicate that spatial variability of both ESR signal intensity and CI is evident within the Taklimakan deserts and the Mongolian Gobi, but less significant in the three deserts of northern China. Coarse-grained quartz from the Mongolian Gobi and northern China deserts can be differentiated from the Taklimakan desert using the ESR signal intensity. Fine-grained quartz originating from three major Asian dust sources, i.e., the Gobi-sandy deserts in western China, northern China and southern Mongolia, can be distinguished effectively using the combination of ESR and CI signals. Our results suggest that ESR signal intensity and CI can discriminate the sources of fine-grained quartz better than coarse-grained quartz, providing an effective approach to trace the provenance of fine-grained dust deposition on the land and in the ocean.

The fundamental peculiarities of discrete diffraction in periodically poled lithium niobate waveguide arrays by applying an electrical field through electro-optics effect are studied. The discrete diffraction properties of such arrays can be effectively altered, depending upon the input conditions. By slightly changing the input conditions, light can experience normal diffraction, anomalous diffraction and even zero diffraction. We show that these three different kinds of discrete diffraction can be modulated by applied voltage in periodically poled lithium niobate waveguide arrays.

Clastic quartz is the main mineral component of the eolian loess.The Crystallinity Index(CI) of clastic quartz is related to the type of mother rock,and the quartz content(QC) can be used to estimate the dust flux change so as to restore the desertification history of the source area.The paper discussed in details the testing conditions and data processing methods,and the errors they may cause to the estimation of QC and CI.It is concluded that(1) The scanning step size and speed should be different when CI and QC are measured separately;(2) Before the data processing,the background should be deducted manually.CI was estimated by the diffraction peak value at 67.74° and the diffraction valley value at 67.85°,and the estimation of QC mainly depends on the diffraction quartz peak value at 20.9° and diffraction silicon peak value at 28.4°;(3) CI should be the average of repeated measurement by pressed methods.

The Asian Monsoon forms an important part of the earth’s climate system, yet our understanding of the past interactions between its different sub-systems, the East Asian and Indian monsoons, and between monsoonal winds and other prevailing wind currents such as the Westerly jet, is limited, particularly in central Asia. This in turn affects our ability to develop climate models capable of accurately predicting future changes in atmospheric circulation patterns and monsoon intensities in Asia. Provenance studies of mineral dust deposited in terrestrial settings such as peat bogs can address this problem directly, by offering the possibility to examine past deposition rates and wind direction, and hence reconstruct past atmospheric circulation patterns. However, such studies are challenged by several issues, most importantly the identification of proxies that unambiguously distinguish between the different potential dust sources and that are independent of particle size. In addition, a single analytical method that is suitable for sample preparation of both dust source (i.e. desert sand, soil) and receptor (i.e. dust archive such as peat or soil profiles) material is desirable in order to minimize error propagation derived from the experimental and analytical work. Here, an improved geochemical framework of provenance tracers to study atmospheric circulation patterns and palaeomonsoon variability in central Asia is provided, by combining for the first time mineralogical as well as major and trace elemental (Sc, Y, Th and the rare earth elements) information on Chinese (central Chinese loess plateau, northern Qaidam basin and Taklamakan, Badain Juran and Tengger deserts), Indian (Thar desert) and Tibetan (eastern Qinghai–Tibetan Plateau) dust sources. Quartz, feldspars and clay minerals are the major constituents of all studied sources, with highly variable calcite contents reflected in the CaO concentrations. Chinese and Tibetan dust sources are enriched in middle REE relative to the upper continental crust and average shale but the Thar desert has a REE signature distinctly different from all other dust sources. There are significant differences in major, trace and REE compositions between the coarse and fine fractions of the surface sands, with the finest 2 O 3 , Fe 2 O 3 , MnO, MgO and K 2 O and the ∗ (all REE normalized to post-Archean Australian shale, PAAS) are particle size-independent tracers, of which combinations of Y/∑REE, La/Yb, Y/Tb, Y/La and Eu/Eu ∗ can be used to distinguish the Thar desert, the Chinese deserts, the Chinese loess plateau and the Tibetan soils. Their independence upon grain size means that these tracers can be applied to the long-range provenance tracing of Asian dust even when only bulk samples are available in the source region. Combinations of La/Th, Y/Tb, Y/∑REE, Sc/La and Y/Er distinguish the Tibetan soils from the Chinese loess plateau and the Chinese deserts. La/Th and notably Th/∑REE isolate the signature of the Badain Juran desert and the combination of Sc/La and Y/Er that of the Taklamakan desert. The similarity in all trace and REE-based provenance tracers between the northern Qaidam basin and Tengger desert suggests that these two deposits may have a common aeolian source.

Crash distributions and the locations of all crashes and severe crashes at freeway diverging areas were analyzed and compared. Contributing factors to crashes were identified; these included exit ramp types, geometric design features, traffic conditions, and crash-related attributes. Exit ramp types are defined by the number of lanes exiting freeways and AASHTO's lane-balance theory. Four typical exit ramp types were considered: one-lane exit with lane-balanced design (Type 1), one-lane exit with lane-unbalanced design (Type 2), two-lane exit with lane-balanced design (Type 3), and two-lane exit with lane-unbalanced design (Type 4). Lanes are further classified as exit and drop lane group, impact lane group, and interior lane group. Proportionality tests were used to compare the crash distributions on different lanes. The results indicate that lane-balanced designs (Type 1 and Type 3) have a statistically significant higher percentage of severe crashes on the impact lane group than that for lane-unbalanced designs (Type 2 and Type 4). For the interior lane group, Type 4 ramps have a statistically significant higher percentage of severe crashes than the other design types. In addition, ordered probit models were developed for all crashes and severe crashes by one-lane exits and two-lane exits, respectively. Outcomes from the models suggested that more crashes occurred on the exit and drop lane group for the lane-unbalanced designs and more severe crashes occurred on the interior lane group for the lane-unbalanced designs. The study will help engineers have a better understanding of crash distributions and locations for different exit types and help them to develop effective countermeasures.

The number and arrangement of lanes on freeways are important considerations in freeway geometric design. The objective of this study is to evaluate the safety impacts of lane arrangements on freeway segments with closely spaced entrance and exit ramps. Three different types of lane arrangements were considered. They were designated as Type A, Type B, and Type C arrangements. The research team compared crash frequency, crash rate, crash severity, and collision types for freeway segments with different types of lane arrangements. Crash prediction models were developed to relate crash counts to various explanatory variables such as traffic conditions and geometric characteristics. The crash data analysis results show that the Type C arrangement reported the lowest average crash frequency and crash rate. The Type C arrangement uses a continuous auxiliary lane to connect the entrance and exit ramps; and the auxiliary is dropped in a one-lane exit. Freeway segments with the Type B arrangement reported the highest average crash frequency, crash rate, and percentage of fatal plus severe injury crashes. Based on the crash prediction models, if other factors remain constant, a Type B arrangement results in 113% more total crashes and 102% more severe crashes than does a Type C arrangement. Crash data analysis results suggest that the Type B arrangement should be used cautiously when entrance and exit ramps are closely spaced.

Films of layered double hydroxides (M/Al-LDHs) with M=Ni, Zn have been fabricated on a porous anodic alumina/aluminum (PAO/Al) substrate via an in situ crystallization technique. The Ni/Al-LDH film has an orientation in which the ab- faces of the platelets are all perpendicular to the substrate whilst the LDH crystallites in the Zn/Al-LDH film are randomly orientated. Furthermore, the interlayer galleries of Ni/Al-LDH contain CO 3 2 - anions whereas NO 3 − anions were found in the interlayer galleries of Zn/Al-LDH. These differences between the Ni/Al-LDH and Zn/Al-LDH films are, at first sight, surprising because the films were fabricated under identical experimental conditions. Two different mechanisms, homogeneous nucleation and the heterogeneous nucleation, have been proposed in order to account for the different growth processes of the Ni/Al-LDH and Zn/Al-LDH films, respectively. The two distinct growth mechanisms can satisfactorily account for the different crystallite orientations and types of interlayer ion in the M/Al-LDH (M=Ni, Zn) films.

The wetting properties of two types of superhydrophobic layered double hydroxide (LDH) films modified by treatment with laurate (La) anions, NiAl–CO32-–LDH/La film and ZnAl–La–LDH film, have been investigated using the sessile drop and Wilhelmy plate methods. The spreading kinetics of water droplets on ZnAl–La–LDH film surfaces was fitted by a power equation, and an effective lubrication coefficient was calculated. Unlike one-cycle measurements reported in a number of earlier studies, cycling contact angle measurements using the Wilhelmy plate method provide more information about the mechanism of contact angle hysteresis. Both the advancing contact angles (θa) and the receding contact angles (θr) of NiAl–CO32-–LDH/La film—in which the La anions are adsorbed on the surface of the LDH—obtained in different cycles were found to be independent of cycle number. In contrast, for the ZnAl–La–LDH film—in which the La anions are intercalated into the interlayer galleries of the LDH—the advancing contact angles (θa) and the receding contact angles (θr) obtained in different cycles were found to vary. It was found that both θa and θr decreased with increasing number of cycles. The different contact angle hysteresis behaviors were qualitatively and quantitatively investigated by means of dynamic contact angle analysis. The results suggest that contact angle hysteresis of NiAl–CO32-–LDH/La and ZnAl–La–LDH films can be ascribed to dynamic hysteresis and intrinsic hysteresis, respectively.

We propose that domain inversion can be directly induced by femtosecond laser both theoretically and experimentally, which opens a path to achieve three-dimensional (3D) nonlinear crystal with a period in sub-micron-scale. A simulation of domain inversion is modeled by considering the temporal distribution of femtosecond pulses. The calculation results clarify that the domain inversions can happen within or after the interaction with the laser pulse, and the response time of domain inversion is in the picosecond level depending on the intensity and the materials. The domain reversal windows of lithium niobate by femtosecond laser are observed which agrees with theoretical predictions qualitatively. OCIS codes: 320.0320, 160.0160, 310.0310. doi: 10.3788/COL20090702.0169.

Mixed metal oxide (MMO) films containing Ni2+ and Al3+ have been fabricated by a simple process involving calcination of layered double hydroxide (LDH) film precursors at 300−600 °C for 4 h in air. Scanning electron microscopy (SEM) reveals that the resulting Ni/Al−O thin films maintain the original nestlike morphology of the precursor films without any deformation of the microstructure during the thermal decomposition process. After surface treatment with an aqueous solution of sodium laurate, the wettability of the NiAl-LDH and Ni/Al−O thin film surfaces changes from hydrophilic to hydrophobic. Moreover, whereas the NiAl-LDH film exhibits a low adhesion for water (Cassie−Baxter behavior) after surface modification, the Ni/Al−O films exhibit a high adhesion for water (Wenzel behavior). A possible explanation for this phenomenon has been suggested.

We report measurements of the laser induced breakdown threshold in lithium tantalate with different number of pulses delivered from a chirped pulse amplification Ti: sapphire system. The threshold fluences were determined from the relation between the diameter D 2 of the ablated area and the laser fluence F 0 . The threshold of lithium tantalite under single-shot is found to be 1.84 J/cm 2 , and the avalanche rate was determined to be 1.01 cm 2 /J by calculation. We found that avalanche dominates the ablation process, while photoionization serves as a free electron provider.

We demonstrate a 1×4 waveguide array produced by an IR femtosecond laser in z-cut lithium niobate (LiNbO3). The polarization dependence of light coupling in this waveguide structure is experimentally investigated. The coupling constants of the waveguide array are obtained by measuring the ratio of output power of each waveguide for extraordinary rays and ordinary rays, and the variation of coupled power in each waveguide as a function of the waveguide length are demonstrated.

The fundamental peculiarities of discrete diffraction in the two-dimensional waveguide arrays were studied. The discrete diffraction properties of such arrays can be effectively altered, depending upon the input conditions. By slightly changing the input conditions, light can experience normal diffraction in one-direction and experience anomalous diffraction in the other.

Parallel embedded waveguides are fabricated from a computer-aided design file by scanning the focus spot in z-cut lithium niobate (LiNbO3) using femtosecond laser pulses. The beam coupling in such waveguides is experimentally investigated. The coupling constant of the waveguide structure is obtained by measuring the ratio of output power of each waveguide, and the variation of coupled power in each waveguide as a function of the waveguide length are demonstrated.

High-voltage electrical pulses (HVEP) technology was applied in grinding of a magnetite ore as a comminution pretreatment. The effect of HVEP pretreatment on grindability, liberation and separation performance of a magnetite ore was investigated by a systematic experimental study. The results showed that the pretreatment of high-voltage electrical pulses created some intergranular microcracks inside the ore, reduced the mechanical strength and improved liberation. This gave the additional advantage of further breakage,thereby reducing the energy consumption and grinding time. In addition, the HVEP pretreatment before grinding was potentially beneficial in the recovery of the liberated minerals in the subsequent magnetic separation.

This study investigated the night time crash characteristics at local collectors. The multinomial logit model (MNL) was selected to estimate the contributing factors to different injury outcomes for night time crashes. The latest six-year crash data (2005-2010) were obtained from Florida Crash Annual Report (CAR) System. Five injury level outcomes, no injury, possible injury, non-incapacitating injury, capacitating injury, and fatal injury, were considered. A total of 824 crashes were observed in local collectors. Five explanatory variables, post speed limit, lighting, single vehicle, truck/bus, and age, are significant at a 95% confidence level. Street light presence is the most significant factor to the injury outcome at local collectors and a single vehicle crash could significantly increase the possibility of all injury outcomes compared to a multi-vehicle crash. The odds ratios suggest the having street lights could reduce the relative risk of being in incapacitating injury and fatal injury at local collectors.

Functional vehicle detection and signal system communication are essential for a traffic signal system to execute its intended coordinated signal timing plans. The degradations of vehicle detection and signal system communication could impose barriers to successful operations of a traffic signal system. To achieve and maintain an acceptable operational level set by a traffic agency, an agency has to prioritize its resource allocation. This paper first introduces the concept of traffic signal system performance. It defines a traffic signal system degradation index which measures the proportion of increased travel time attributable to failures in detection and communication components with respect to the total observed travel time of a traffic signal control section. The paper uses the degradation index and traffic simulation to evaluate the effectiveness of major strategies to improve vehicle detection and signal system communication. These strategies include upgrading detection technologies, improving the responsiveness to detection and communication repair work, providing adequate training, increasing the frequency of inspection, and installing a global positioning system (GPS) clock to maintain synchronization of the time clock in the controller. Finally, recommendations for optimal allocation of operation and maintenance resource allocation strategies for traffic signal systems are provided.

In recent years, video surveillance equipments have been applied widely and installed at all major transport nodes. These equipments record a large volume of day-to-day traffic information, which allows measuring the velocity of accident vehicle based on video. Since the early 1980s, researchers have developed various algorithms to extract speed information from traffic image sequences. In this paper, an algorithm is proposed to evaluate the velocity of turn-drive vehicle. The characteristics of an accident scene including the information of lane marks and accident vehicles are utilized to estimate the state of an accident vehicle. With manual interaction, the state of the accident vehicle, including the vehicle trajectory and its speed when it is turning, can be estimated more robustly and accurately. Experimental results show that the proposed approach can capture the accident vehicle’ state accurately and meet the precision demand.

Regeneration of damaged periodontal tissues is mediated by periodontal cells, but a major sub-population comprises highly differentiated cells that do not renew. To overcome the loss of specialized cell types caused by disease, various therapeutic approaches including cell transplants have been developed to promote cell re-population in periodontal tissues. As previous transplantation studies used unlabeled cells, that are indistinguishable from host cells, it has been difficult to assess the contributions of transplanted cells to the healing processes. To track the fate and differentiation of rat periodontal cells transplanted into periodontal wounds, we used collagen-coated fluorescent beads as a permanent endocytosed marker, or cells constitutively expressing beta-galactosidase. We assessed osteogenic cell differentiation with immunohistochemical staining for osteopontin and bone sialoprotein. Cells were transplanted into periodontal wounds created in Sprague--Dawley male rats that are null for beta-galactosidase. Defects were allowed to heal spontaneously (controls), or were closed with collagen implants mixed with beta-galactosidase-positive (Lac-Z) periodontal cells, or closed with collagen implants mixed with periodontal cells loaded with fluorescent beads. Animals were killed at 1 and 2 weeks after surgery and tissues were prepared for morphometric assessment and immunostaining for osteopontin (OPN) and bone sialoprotein (BSP). Transplanted cells were easily distinguished by fluorescent beads or by beta-galactosidase-positive expression and were distributed throughout the regenerating periodontal ligament (PL) and alveolar bone. At 1 week after wounding, animals treated with beta-galactosidase-positive cells exhibited a slightly higher percentage of labeled cells in the PL compared with the fluorescent bead-labeled cell implant group (2% vs. 1% respectively; P > 0.2). At Week 2 percentages of labeled cells were slightly increased in the regenerating PL (approximately 3% for both groups, P > 0.2). In regenerating alveolar bone at 1 week, animals that were treated with beta-galactosidase-positive cells and fluorescent bead-loaded cells exhibited approximately 30% and 25% of labeled cells respectively. At 2 weeks after wounding there was an increase in the percentage of transplanted beta-galactosidase-positive cells (approximately 39% at week 2; P 40%; P < 0.05). Transplantation of beta-galactosidase-positive cells or cells loaded with fluorescent beads is a useful method for assessing the fate and differentiation of periodontal cells in vivo. Fluorescent beads, however, are diluted at mitosis and this method underestimates the percentage of transplanted cells. As transplanted periodontal cells in both groups promoted regeneration of alveolar bone, cell transplantation could improve the restoration of periodontium destroyed by periodontitis.

In order to study the settlement characteristic of ram-compacted piles with bearing base (RPBB), pile-raft composite foundation in high-speed railway, RPBB, and Cement Fly-ash Gravel (CFG) piles were tested and compared under the Beijing-Shanghai high speed railway. Using hydrostatic levels, the settlements of test sections were monitored over the long term. Results show, because of the formation conditions and the construction technology of RPBB, the reinforced depth of RPBB is limited. Consequently, the settlement of RPBB is bigger than CFG. It also takes longer to reach stable settlement for RPBB. In addition, based on measured and modified soil compression modulus, the thicknesses of compressed layers and the settlements were calculated using control strain method and control stress method. The calculated results using control strain method and modified soil compression modulus are reasonably close to the testing data. This proves that the modified soil compression modulus can improve the precision and reliability of the settlement estimation. This can overcome the limitations of existing Chinese code.

This paper studies the cause of traffic accidents occurred at the road intersection in night. Research status of road intersection safety at home and abroad is summarized. Considering the actual situation of China's road intersection, five measures as setting perspective barrier, convex mirror, reflection facility, lighting equipment and removing obstacle are proposed in order to prevent traffic accidents occurred on the road intersection at night. This method gives a good idea on economic and effective safety measures at the road intersection.

The ribosome binding site (RBS) of prokaryotic mRNA is divided into 5′ and 3′ portions by the translation initiation codon. Although it is well known that the presence of an appropriate RBS containing only the 5′ portion is sufficient to direct the initiation of protein synthesis, the 3′ portion appears to play a significant role in modulating the initiation process as well. Here we examine the influence of adenine-rich motifs frequently found in the 3′ portion of highly expressed prokaryotic mRNAs. Two synthetic DNA fragments, GAGAAAAAAATC (corresponding to the first 12 nucleotides following the initiation codon of the chloramphenicol acetyltransferase gene), and AAAAAAATTAA were used to modify the beginning of the coding region of the human immune interferon-γ (IFN-γ) gene. The level of the protein synthesis in Escherichia coli directed by plasmids containing these constructs was quantitated. We found that placing either adenine-rich motif in the 3′ portion of the RBS strongly enhanced gene expression, probably through an effect on translation initiation. We have also compared the protein expression levels of these gene constructs containing different series of 5′-RBSs with varying precistronic lengths and Shine-Dalgarno sequence lengths. The results suggest a positive functional role for the 3′ adenine-rich motif. A possible mechanism for these effects is discussed.

The prokaryotic mRNA ribosome binding site (RBS) usually contains part or all of a polypurine domain UAAGGAGGU known as the Shine-Dalgarno (SD) sequence found just 5' to the translation initiation codon. It is now clear that the SD sequence is important for identification of the translation initiation site on the mRNA by the ribosome, and that as a result, the spacing between the SD and the initiation codon strongly affects translational efficiency (1). It is not as clear, however, whether there is a unique optimal spacing. Complications involving the definition of the spacing as well as secondary structures have obscured matters. We thus undertook a systematic study by inserting two series of synthetic RBSs of varying spacing and SD sequence into a plasmid vector containing the chloramphenicol acetyltransferase gene. Care was taken not to introduce any secondary structure. Measurements of protein expression demonstrated an optimal aligned spacing of 5 nt for both series. Since aligned spacing corresponds naturally to the spacing between the 3'-end of the 16S rRNA and the P-site, we conclude that there is a unique optimal aligned SD-AUG spacing in the absence of other complicating issues.

This study aims to examine the deceleration lane lengths on operational effects by two-lane exits and present the optimal design length under different combinations of traffic and geometric conditions. Traffic simulation results indicate that it is benefitial to use the longer deceleration lane length to minimize the impact of exiting traffic on the through movement vehicles. A maximal of 18.2 % reduction of the delay is obtained under the exiting volume of 2000 vph by replacing the 100 ft long deceleration lane with 1000 ft at the design speed of 55 mph. A minimal distance of 400 ft and 500 ft was recommended at the design speeds of 55 mph and 60 mph. At the design speeds of 65 mph and 70 mph, a deceleration lane was recommended to be longer than 600 ft. Since there is no clear standard of the minimal deceleration lane length for the two-lane exit, the results from this study could be used as a design guideline for the two-lane exits.

The dynamic approach has been widely applied to measure the velocity of accident vehicles, while it is difficult to perform sometimes due to the shortage of parameters. In this paper, the algorithm is proposed to measure the velocity of the accident vehicle based on morphology of broken vehicle windshield glass. A relationship model between the velocity of accident vehicle and objects’ parameters which include structure, quality and speed before collision was established by image processing technology. Five different types of collision objects, in different velocities are selected to simulate the collision process. The results show that, the concentration area of broken vehicle windshield glass is decided by the velocity and quality of the collision objects, the morphology of broken vehicle windshield glass is related to the velocity, quality and structure of the collision objects. Good idea is given to reconstruct the velocity of the vehicle velocity based on the morphology of broken glass.

Safety Analyst (SA) is a newly released software package that is designed to help state-wide or local agencies with a strong improvement of highway safety management on a basis of cost-effectiveness procedures. This study aims to help the potential SA users to better understand the methodologies, implementation procedures, and benefits of SA by four analytical tools. The case study was conducted at a 14.8 mile long corridor on Interstate 275 (I-275) in Tampa with the crash data in 2007. The network screening tool, diagnosis and countermeasure tool, and economical appraisal tool, are performance at the three highest-rank sites for potential safety improvements by SA. For practical purpose, this analysis could be used as an initial implementation before the widely application of the software.

Adaptive traffic control systems continuously monitor traffic conditions on an arterial and adjust traffic signal timings to accommodate variation in traffic volume and minimize stops and delays. This paper describes currently practical adaptive control systems which have been used in the United States and worldwide, which include Adaptive Control System-Lite (ACS-Lite), Optimization Policies for Adaptive Control (OPAC), Real-Time Hierarchical Optimized Distributed and Effective System (RHODES), Sydney Coordinated Adaptive Traffic System (SCATS) and Split Cycle Offset Optimization (SCOOT). The comparisons of the benefits from past experiences, cost and hardware requirements will help the traffic engineers and decision makers a guideline to select the optimized adaptive control system based on research objectives.

The fabrication of waveguides inside transparent media using ultrashort laser pulses has gained a lot of interest during the past years. When femtosecond laser pulses are focused inside the bulk of transparent materials, the refractive-index change can be induced around the focal volume. In this paper, we demonstrate that embedded waveguides are fabricated from a computer-aided design file by scanning the focus spot in z-cut lithium niobate (LiNbO 3 ) using femtosecond laser pulses. The beam coupling in such waveguides is experimentally investigated. The coupling constant of the waveguide structure is obtained by measuring the ratio of output power of each waveguide.

The safety performance of left-side off-ramps was evaluated by comparing that of right-side off-ramps at freeway diverge areas. Crash records at a total of 11 left-side and 63 similar right-side diverge areas in Florida were collected. Based on the data collected, the traffic conflict study and the cross-sectional comparison of crashes were conducted in this study. Four types of traffic conflicts were identified and counted. The average conflict rates near the ramp area were found to be approximately 10 per 1000 conflicting vehicles. Crash data were compared for the left-side off-ramps with right-side off-ramps by two exit ramp types: one-lane exit and two-lane exit with an optional lane, respectively. The comparisons indicate that the left-side off-ramp did have higher average crash counts, crash rate and percentage of severe crashes, but the difference is only statistically significant for the severe crashes at a 10% level. A crash prediction model for one-lane exit was developed to identify the factors that contribute to the crashes that have been reported for selected freeway segments. The conclusion is consistent with cross-sectional comparison. It is expected that this study could help engineers have a better understanding of left-side off-ramps at freeway diverge area and select the appropriate countermeasures and practical designs.

The fabrication of waveguides inside transparent media using ultrashort laser pulses has gained a lot of interest during the past years. When femtosecond laser pulses are focused inside the bulk of transparent materials, the refractive-index change can be induced around the focal volume. Usually, only one waveguide was produced by the femtosecond laser when the sample moved one time. In this paper, we demonstrate that multiple waveguides can be fabricated simultaneously by femtosecond laser pulses using a multiple foci approach inside fused silica glasses. It is realizable for placing an array of slits before the focusing system to control the spatial distribution of laser pulses. The femtosecond laser beam is split by the array of slits and simultaneously focused at different areas by a microscope objective.

The primary objective of the study is to evaluate safety performances of different exit ramps used in Florida. More specific, the research objectives include: (1) to evaluate the impacts of different ramp configurations on safety performance; and (2) to identify the different factors contributing to the crashes happening on the exit ramp sections. 389 sites were investigated throughout Florida by four ramp configurations, diamond, out connection, free-flow loop and parclo loop. Cross-sectional comparisons and crash predictive model were used to quantify the impacts. The result shows that the out connection ramps appear to have the lowest average crash. The predictive model indicates that replacing an out connection exit ramp with a diamond, free-flow, and parclo loop will increase crashes counts by 26.90%, 68.47% and 48.72% respectively. This study will help transportation decision makers develop technical guidelines governing the selection of the optimum design on freeway exit ramps.

In this study, a procedure was developed to help transportation professionals evaluate the impacts of U-turns on level of service of signalized intersections using two widely used simulation packages: Synchro and SimTraffic. Two parameters related to U-turns were calibrated based on field data. They are (1) the saturation flow rate for U-turn and left-turn mixed traffic stream; and (2) the turning speeds for U-turning vehicles in the left-turn lane. The saturation flow rate was calculated based on the U-turn adjustment factors developed in a previous study. A linear regression model was developed for predicting the average turning speeds of U-turning vehicles at a signalized intersection given the turning radius provided at the left-turn bay. Delay reported by the calibrated Synchro and SimTraffic models was compared to the average control delay measured in the field. The effectiveness of parameter calibration differs for different signalized intersections. It was generally found that the calibrated Synchro and SimTraffic models provided reasonable delay estimates for U-turns at signalized intersections. With the calibrated and validated Synchro and SimTraffic models, sensitivity analysis was conducted to evaluate how the increased number of U-turning vehicles affects the level of service of signalized intersections. It was found that the sensitivity of the average control delay to changing U-turn volumes differs for different signalized intersections. The sensitivity analysis results suggest that the impacts of U-turns on the level of service of signalized intersections shall be evaluated on a case-by-case basis.