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Verticality check of prefabricated elements is an essential part of prefabrication construction. Currently, it is mostly carried out by manual methods, which is slow and inefficient. Previous studies have used laser scanning for the quality check but mainly focused on surface defects, flatness, and the dimension of construction elements. Very few studies used laser scanning to evaluate the installation quality of prefabricated elements. Those, who adopted the laser scanning method, compared the as-built with the initial design version of BIM. Such approach requires an accurate design version of BIM with tedious manual tasks relying on human skills that involve errors. This on-going study investigates a verticality check method based on laser scanning for assessing the quality of wall panel installations without relying on previous drawings or BIM. The proposed method enables practitioners to confirm the quality of the wall panel installation and its vertical deviations based on the processed point cloud data. The region growing segmentation and random sample consensus are used to process the acquired data for computing the deviations. This method is validated in a real high-rise prefabrication residential building. Our method took about 9 min/100 m2, versus the conventional method, which took 31 min/100 m2. The experiments indicate that the proposed method is significantly more time-efficient compared to the conventional manual method. The contribution of this study includes suggesting suitable parameters for measuring the vertical dimensions of prefabricated wall panels and deviations that can be replicated in high-rise prefabricated residential projects.

Present urbanization influences urban morphology by the increasing number of dense buildings and infrastructure, which effects climate change. Microclimate simulations including urban vegetation help in mitigating climate change. Most of existing microclimate simulations simplify trees and thereby may introduce some erroneous estimates. Tree models of high levels of detail (LOD) can provide a more accurate measure. Technology advances make it possible to reconstruct detailed tree models, which can be further used in microclimate simulations. However, the few studies presenting detailed tree models focus predominantly on the reconstruction process and omit the microclimate simulations. The objective of this study is to investigate high LOD tree models in microclimate simulation to estimate the potential gain in accuracy. This study focuses on voxel-based tree models and microclimate simulations using computer fluid dynamics software. A series of microclimate simulations are completed in two scenarios, which are single tree and a set of trees with buildings. Based on the simulation results, the advantages of detailed voxel tree models are demonstrated. Final discussion elaborates on the needed and preferred levels of detail for tree models.

Abstract Background Non-traumatic hemoperitoneum was a rare event with the risk of sudden death. Spontaneous rupture of hepatocellular carcinoma is the most intuitive diagnosis when hemoperitoneum occurs in cirrhotic patients who are not regularly followed up. However, other etiologies of hemoperitoneum, such as intra-abdominal varix rupture, should be kept in mind. Case presentation A 44-year-old man with alcoholic liver cirrhosis, Child–Pugh B was sent to our emergency department (ED) because of recurrent abdominal pain and hypovolemic shock. He had similar symptoms one month ago and was diagnosed as hepatocellular carcinoma (HCC) rupture with hemoperitoneum, therefore he underwent trans-arterial embolization (TAE). However, the follow-up magnetic resonance imaging (MRI) showed less possibility of hepatocellular carcinoma. Contrast enhanced abdominal computed tomography (CT) showed possible umbilical vein contrast agent extravasation. Exploratory laparotomy confirmed the diagnosis of rupture umbilical varix with hemoperitoneum. Conclusion Although umbilical varix rupture is a rare cause of hemoperitoneum, it should be kept in mind in cirrhotic patients with unexplained hemoperitoneum.

Illumination-insensitive image representation is a great challenge in the computer vision field. Illumination variations considerably obstruct the effectiveness of image feature extraction. In this paper, we present a novel and generalized learning framework for illumination-insensitive image representation, which can learn the discriminative features through maximizing the inter-difference and minimizing intra-difference of the images with boosting. Particularly, we enhance the discriminative capacity of illumination-insensitive image representation in three aspects. First, we learn a subset of different synergistic Weber excitation patterns (SWEP) to generate the dominant SWEP (DSWEP) and DSWEP codebook for exploring optimal illumination-insensitive patterns. Second, a compact DSWEP (C-DSWEP) is learned with a boosted set of weight to generate C-DSWEP codebook. Discriminative learning is aimed at robustness and compactness. Third, the discriminative histogram learning model is established for encoding CDSEP to further improve the discriminative ability and reduce redundancy. The extensive experiments on CMUPIE, FERET, Yale B, Yale B ext., LFW, and PhoTex databases have highlighted the superiority and the robustness of our method compared with some other state-of-the-art methods.

The harmonic operation in a terahertz gyrotron traveling-wave amplifier (gyro-TWA) permits a reduced magnetic field, whereas a harmonic multiplying gyro-TWA enables magnetic field reduction and frequency multiplication. This study comparatively analyzes the 400-GHz fourth-harmonic gyro-TWAs and fourth-harmonic multiplying gyro-TWAs with axis-encircling electron beams. This property of the gyro-TWAs with axis-encircling electron beams enables us avoid the appearance of the majority of the competing modes. According to the simulation results obtained using multi-mode codes, the attenuating severs suppress the remaining competing modes. In the case of a harmonic gyro-TWA containing a sever section, the copper-section start-oscillation length is significantly influenced by a decrease in the sever-section radius when compared with an increase in the sever-section length. Furthermore, a stable fourth-harmonic TE41-mode gyro-TWA containing sever sections is proposed. We propose fourth-harmonic TE41-mode multiplying gyro-TWAs, where the drive stages operate in the fundamental-harmonic TE11 mode to reduce the frequency of the drive wave. We subsequently develop a stable fourth-harmonic multiplying gyro-TWA with sever sections in the drive and amplified stages to avoid the competing modes and enhance the output power. The stable high-gain fourth-harmonic gyro-TWA can yield a peak output power of 2.7 kW at 400.6 GHz with a saturated gain of 75 dB and a bandwidth of 0.7 GHz for a 75-kV and 2-A electron beam with an axial velocity spread of 3%. Furthermore, a peak output power of 1.7 kW can be obtained by the fourth-harmonic multiplying gyro-TWA at 400.4 GHz with a saturated gain of 57 dB and a bandwidth of 0.4 GHz. Subsequently, we calculate the power and gain scaling for the harmonic gyro-TWA and harmonic multiplying gyro-TWA.

Abstract Abyssal manganese nodules have been explored widely for their economic potential and paleoenvironmental significance. Debate about whether biogenic or physical‐chemical processes are responsible for their formation remains because of difficulties in quantifying ancient microbiological contributions. To address this question, we investigated microbial fossils in manganese nodules from the western Pacific Ocean by integrating scanning electron microscope, transmission electron microscope, and synchrotron transmission X‐ray microscope observations. Our results suggest that the nodules host abundant fossil biogenic magnetite and manganese‐oxidizing bacteria. These organisms engage in redox reactions or live in environments with redox gradients. By combining magnetic properties and observations of fossil biogenic magnetite morphology, we estimate magnetofossil abundances and further assess fossil biogenic manganese oxide in nodules. Our results imply that manganese nodule formation appears to be dominated by biomineralization with an additional terrestrial contribution. Extensive biomineralization in ultralow‐productivity oceanic environments suggests that manganese nodule formation is an important aspect of biogeochemical cycling in abyssal seafloor environments.

A heavily germanium-doped (Ge-doped) silica fiber with a four-layer refractive index profile is proposed to obtain all normal flat dispersion property. The waveguide dispersion in the fiber can be modified by adjusting the fiber parameters, including the refractive indices and the core radiuses. As a result, the flat normal dispersion in the fiber can be obtained in the wavelength range of 1540-2600 nm, where the values of the dispersion slope are between -0.0058 and 0.03 ps/nm2/km. Furthermore, the numerical results show that the flat-top supercontinuum spectrum ranging from 1000 to 2600 nm can be generated by launching pump pulses at the wavelength of 1550 nm in the heavily Ge-doped fiber with a four-layer refractive index profile.

The temperature and pressure-dependent dielectric functions of liquids are of great importance to the thermal radiation transfer and the diagnosis and control of fuel combustion. In this work, we apply the state-of-the-art ab initio molecular dynamics (AIMD) method to calculate the infrared dielectric functions of liquid methanol at 183–573 K and 0.1–160 MPa in the spectral range 10−4000 cm−1, and study the temperature and pressure effects on the dielectric functions. The AIMD approach is validated by the Infrared Variable Angle Spectroscopic Ellipsometry (IR-VASE) experimental measurements at 298 K and 0.1 MPa, and the proposed IR-VASE method is verified by comparison with paper data of distilled water. The results of the AIMD approach agrees well with the experimental values of IR-VASE. The experimental and theoretical analyses indicate that the temperature and pressure exert a noticeable influence on the infrared dielectric functions of liquid methanol. As temperature increases, the average molecular dipole moment decreases. The amplitudes of dominant absorption peaks reduce to almost one half as temperature increases from 183 to 333 K at 0.1 MPa and from 273 to 573 K at 160 MPa. The absorption peaks below 1500 cm–1 show a redshift, while those centered around 3200 cm–1 show a blueshift. Moreover, larger average dipole moments are observed as pressure increases. The amplitudes of dominant absorption peaks increase to almost two times as pressure increases from 1 to 160 MPa at 373 K.

In the traditional run-to-run (R2R) control scheme, the controller provides the feedback strategy, enabling each run of process output to remain as close to the target as possible. However, in practice this process encounters bottlenecks if all the runs are started with a control parameter adjustment, as this will increase process variation in the stable process. In this paper, an improved R2R control scheme is developed to add an adjustments limitation technique to both the EWMA controller and the self-tuning controller. From the simulation, analysis of the results shows that the proposed procedure can effectively reduce the frequency of controller adjustments, without affecting the capability of the original controller. Therefore, in practical applications, the proposed control framework can be used to prevent the problem of process over-control.

A series of Co-doped ZnO thin films were prepared under various deposition conditions using the pulsed laser deposition method. X-ray photoelectron spectroscopy (XPS) and XPS depth profiling were used to detect the elemental valence states of Zn, Co and O. It was found that the films deposited under low temperature and high oxygen pressure exhibited intrinsic ferromagnetic properties due to oxidation of Co (Co2+) from the material. However, when the films were deposited under high temperature and low oxygen pressure, metallic cobalt (Co0) appeared and the ferromagnetism was greatly enhanced.

c-axis preferential orientated ZnO:Co thin films were synthesized on c-plane sapphire substrates by using pulsed laser deposition (PLD) technique in an oxygen-deficient ambient. X-ray diffraction spectra, scanning electron microscopy, X-ray photoelectron spectroscopy, energy dispersive spectroscopy, UV-vis transmittance spectra, and Raman spectra were used for characterization. Ferromagnetic behavior was clearly observed at room temperature and verified to be the intrinsic property of the material. The presence of second phase was ruled out.

Sr2CoNbO6 ceramics were prepared via the solid-state reaction route. The dielectric properties of Sr2CoNbO6 ceramics were investigated as a function of temperature (90–330 K) in the frequency range from 20 Hz to 10 MHz. Our results reveal that the dielectric properties of Sr2CoNbO6 are closely linked with the conductivity of the sample. The conductivity is dominated by hopping localized carriers. The hopping process not only produces considerable conductivity followed the universal dielectric response behavior, but also gives rise to dipolar effects leading to the polaron relaxation in intermediate-temperature range. At low enough temperatures, the hopping process is frozen-in and the low-temperature Maxwell-Wagner relaxation due to frozen carriers featuring the nearly constant loss behavior appears. At higher temperatures, the long-distance transportation of the carriers becomes remarkable. These carriers are easily blocked by various interfaces resulting in space charge therein and the conventional Maxwell-Wagner relaxation in the high-temperature range. Our results demonstrate that a multirelaxation mechanism instead of a single relaxation underlies the colossal dielectric properties of Sr2CoNbO6.

First, by using of the conventional Rowell analysis, we demonstrated that the addition of nano BN particles can effectively eliminate MgO and pores in MgB2 resulting in a very high density and good connectivity of BN-doped MgB2. Then, another method—low-frequency dielectric impedance analysis—was introduced to characterize the properties of the grain boundaries of MgB2. A comparative impedance study was performed in the frequency range from 100 Hz to 100 MHz on pure and nano BN-doped MgB2. The study revealed some following interesting results: (1) a dielectric resonance around frequency of 108 in both samples was observed, which was argued to be related to an inductance-capacitance and (2) the pure sample has two dielectric relaxations originating from intergrains, while the doped sample has only one intergranular contribution. This convinces that the electric connectivity of the doped sample is really improved by the addition of nano BN particles. Our results indicate that dielectric technique may be a useful tool to characterize the grain boundary properties and grain boundary-related properties of MgB2. [ABSTRACT FROM AUTHOR]

The analysis of crystal structure of particulate methane monooxygenase (pMMO), membrane-bound metalloenzyme isolated from Methylococcus capsulatus is described. The results reveal that the C-terminal subdomain folds into a [beta]-sheet structure in the presence of Cu(I) which facilitates the function in the turnover of the enzyme.

The planar Hall effect (PHE) at the junction of two orthogonal 200-nm-wide Co wires is described. Both the experimental and simulated PHE curves expose that the magnetization switching at the junction is strongly linked up with the reversal processes of the individual wire.

The effect of electrical contact geometry on the shape and sign of the magnetoresistance (MR) response in micron-size antirectangular array structures like Ni80Fe20, are investigated. The results can be attributed to the competing anisotropic MR effects from two inhomogeneous orthogonal current flows in the structure.

Summary: In the human pathogenic mold Aspergillus fumigatus, sexual identity is determined by the mating‐type idiomorphs MAT1‐1 and MAT1‐2 residing at the MAT locus. Upon crossing of compatible partners, a heterothallic mating is executed to eventually form cleistothecia that contain recombinant ascospores. Given that the MAT1 gene products are DNA binding master regulators that govern this complex developmental process, we monitored the MAT1‐driven transcriptomes of A. fumigatus by conditional overexpression of either MAT1 gene followed by RNA‐seq analyses. Numerous genes related to the process of mating were found to be under transcriptional control, such as pheromone production and recognition. Substantial differences between the MAT1‐1‐ and MAT1‐2‐driven transcriptomes could be detected by functional categorization of differentially expressed genes. Moreover, a significant and distinct impact on expression of genetic clusters of secondary metabolism became apparent, which could be verified on the product level. Unexpectedly, specific cross‐regulation of the fumagillin/pseurotin supercluster was evident, thereby uncoupling its co‐regulatory characteristic. These insights imply a tight interconnection of sexual development accompanied by ascosporogenesis with secondary metabolite production of a pathogenic fungus and impose evolutionary constraints that link these two fundamental aspects of the fungal lifestyle. Sexual identity and reproduction of fungi is determined by master regulators encoded on specified mating‐type loci. Forced expression of the idiomorphic mating‐type genes MAT1‐1 and MAT1‐2 of Aspergillus fumigatus and profiling the MAT1‐driven transcriptomes lead to the characterization of sex‐specific secondary metabolomes of this human pathogenic mould. This illustrates how fungal secondary metabolite production is orchestrated and implies protective measures taken by a heterothallic fungus in the course of progeny formation. [ABSTRACT FROM AUTHOR]

This study analyzed the effect of nonlinear dynamic parameter of phytoplankton toxin emission on the system. Many previous studies have indicated that the zooplankton, mollusks, and habitat factors generate nonlinear chaotic dynamic behavior, which is hardly controlled random behavior. Therefore, in order to understand in what parameter conditions the system has this nonlinear behavior, the linear and nonlinear behaviors resulting from different conditions are discussed. This study used numerical analysis of differential transformation method to analyze the phase of system and applied bifurcation diagrams, trajectory diagrams, Poincaré maps, and spectrograms to discuss and validate whether the system has chaos phenomenon. [ABSTRACT FROM AUTHOR]

The hallmark trait of fungal secondary-metabolite gene clusters is well established, consisting of contiguous enzymatic and often regulatory gene(s) devoted to the production of a metabolite of a specific chemical class. Unexpectedly, we have found a deviation from this motif in a subtelomeric region of Aspergillus fumigatus. This region, under the control of the master regulator of secondary metabolism, LaeA, contains, in its entirety, the genetic machinery for three natural products (fumitremorgin, fumagillin, and pseurotin), where genes for fumagillin and pseurotin are physically intertwined in a single supercluster. Deletions of 29 adjoining genes revealed that fumagillin and pseurotin are coregulated by the supercluster-embedded regulatory gene with biosynthetic genes belonging to one of the two metabolic pathways in a noncontiguous manner. Comparative genomics indicates the fumagillin/pseurotin supercluster is maintained in a rapidly evolving region of diverse fungal genomes. This blended design confounds predictions from established secondary-metabolite cluster search algorithms and provides an expanded view of natural product evolution. [ABSTRACT FROM AUTHOR]

Autumn olive (Elaeagnus umbellata Thunb,) fruit are a rich source of many health-related nutrients. Sweetness is one of the key indicators of quality in this edible fruit. A full-length cDNA for UDP-glucose pyrophosphorylase, an enzyme involved in sugar metabolism, designated EutUGP, was cloned from autumn olive fruit. The open reading frame of EutUGP was 1,431 bp in length, and was interrupted by 18 introns. It encoded a putative polypeptide of 476 amino acids which shared high homology (85 - 87%) with other plant UGPs. The EutUGP gene was highly expressed in fruit and in young stems, but had low levels of expression in roots and leaves. Transcription of EutUGP was up-regulated and reached its maximum in Stage C (dark-yellow) fruit, then decreased slightly in Stage D (full-ripe) fruit. The highest level of accumulation of the EutUGP protein occurred at the full-ripe Stage D. The 953 bp promoter region of the EutUGP gene was isolated using PCR-based DNA-walking. Characterisation of the EutUGP gene and its promoter will contribute to our understanding of its function during ripening in autumn olive fruit. [ABSTRACT FROM AUTHOR]

Auger decay spectra of CO subsequent to O 1s ionization with 549.85 eV photons, i.e. close to the top of the shape resonance, are presented. Their comparison with the normal Auger spectrum recorded at a photon energy well above the shape resonance reveals distinct features. In particular, in the energy region of the O 1s-1→b1Πand O 1s-1→a1Σ+ Auger transitions which are well known to consist of vibrational progressions, additional narrow lines are revealed by the spectra recorded at 549.85 eV. In a detailed fit analysis of these Auger spectra it was possible to show that the newly found lines do not exhibit the expected distortions caused by post-collision interaction. This observation identifies these lines as caused by a different mechanism, such as resonant Auger decay processes of doubly excited states. The transitions are assigned using energy and intensity arguments in combination with complementary angular distribution measurements for the Auger electrons. [ABSTRACT FROM AUTHOR]

A thermo-responsive shape memory polymeric material is reported, which is not only rubber-like from above to below its shape recovery temperature, but also has a repeatable thermal-assisted healing function. The mechanisms behind both features are identified. It is found that while micron-sized inclusions play a part in the shape memory effect (SME), tangled polymer chains contribute to the rubber-like phenomenon and repeatable thermal-assisted healing function atop the SME. This tangling effect enables a perfect combination of high elasticity, SME and repeatable thermal-assisted healing to be simultaneously achieved. [ABSTRACT FROM AUTHOR]

To understand the different environment and morphology for heavy rainfall during 9-10 July 2007, over the Korean Peninsula, mesoscale convective systems (MCSs) that accompanied the Changma front in two different regions were investigated. The sub-synoptic conditions were analysed using mesoscale analysis data (MANAL), reanalysis data, weather charts and Multi-functional Transport Satellite (MTSAT-IR) data. Dual-Doppler radar observations were used to analyse the wind fields within the precipitation systems. During both the case periods, the surface lowpressure field intensified and moved northeastward along the Changma front. A low-level warm front gradually formed with an east-west orientation, and the cold front near the low pressure was aligned from northeast to southwest. The northern convective systems (meso-α-scale) were embedded within an area of stratiform cloud north of the warm front. The development of low-level pressure resulted in horizontal and vertical wind shear due to cyclonic circulation. The wind direction was apparently different across the warm front. In addition, the southeasterly flow (below 4 km) played an important role in generating new convective cells behind the prevailing convective cell. Each isolated southern convective cell (meso-β-scale) moved along the line ahead of the cold front within the prefrontal warm sector. These convective cells developed when a strong southwesterly low-level jet (LLJ) intensified and moisture was deeply advected into the sloping frontal zone. A high equivalent potential temperature region transported warm moist air in a strong southwesterly flow, where the convectively unstable air led to updraft and downdraft with a strong reflectivity core [ABSTRACT FROM AUTHOR]

Endostatin is an important endogenous inhibitor of neovascularization that has been widely used in anti-angiogenesis therapy for the treatment of cancer. However, its clinical application is largely hampered by its low efficacy. Human placenta-derived mesenchymal stem cells (hpMSCs) are particularly attractive cells for clinical use in cell-based therapies. In the present study, hpMSCs were isolated and characterized. We then evaluated the tumor targeting properties and antitumor effects of hpMSCs as gene delivery vehicles for ovarian cancer therapy. We efficiently engineered hpMSCs to deliver endostatin via adenoviral transduction mediated by Lipofectamine 2000. The tropism capacity of the engineered hpMSCs toward tumor cells was then confirmed by in vitro migration assays and in vivo by intraperitoneal injection of hpMSCs into nude mice. The hpMSCs expressing the human endostatin gene demonstrated preferential homing to the tumor site and significantly decreased the tumor volume without apparent systemic toxic effects. These observations were associated with significantly decreased blood sprouts and tumor cell proliferation as well as a dramatically increased tumor apoptosis index. These results suggested that hpMSCs are potentially an effective delivery vehicle for therapeutic genes for the treatment of ovarian cancer. [ABSTRACT FROM AUTHOR]

This study proposes and examines a circular composite bridge pier for seismic resistance. The axial and flexural strengths of the proposed bridge pier are provided by the longitudinal reinforcing bars and the concrete, while the transverse reinforcements used in the conventional reinforced concrete pier are replaced by the steel tube. The shear strength of this composite pier relies on the steel tube and the concrete. This system is similar to the steel jacketing method which strengthens the existing reinforced concrete bridge piers. However, no transverse shear reinforcing bar is used in the proposed composite bridge pier. A series of experimental studies is conducted to investigate the seismic resistant characteristics of the proposed circular composite pier. The effects of the longitudinal reinforcing bars, the shear span-to-diameter ratio, and the thickness of the steel tube on the performance of strength, ductility, and energy dissipation of the proposed pier are discussed. The experimental results show that the strength of the proposed circular composite bridge pier can be predicted accurately by the similar method used in the reinforced concrete piers with minor modification. From these experimental studies, it is found that the proposed circular composite bridge pier not only simplifies the construction work greatly but also provides excellent ductility and energy dissipation capacity under seismic lateral force. [ABSTRACT FROM AUTHOR]

A theoretical model for the two-dimensional, incompressible, and steady-state laminar forced convective flow over the irregular wafer is examined. Starting from the full Navier–Stokes equations and converting this into the boundary layer equations by the simple coordinate transformation. The resulting parabolic equations are solved using the cubic spline approximation. The numerical result shows that the local flow and local heat transfer characters of a wafer surface are greatly affected by the tiny concaves and convexes on the surface and have a frequency similar to that of surface geometry. The effect becomes obvious with the increase of radius, whereas the mean heat transfer efficiency remains slightly less than that of flat wafer. [ABSTRACT FROM AUTHOR]

Proficient production of the antitumor agent triostin A was developed using engineered Escherichia coli(E. coli). The bacterium played host to 15 genes that encode integral biosynthetic proteins which were identified and cloned from Streptomyces lasaliensis. In this study, triostin A production was dramatically increased by more than 20-fold, 13 mg/L, with the introduction of exogenous quinoxaline-2-carboxylic acid (QXC), the speculative starting unit for biosynthesis of triostin A. Conversely, de novoproduction of triostin A by means of high cell density fed-batch fermentation that is exclusive of exogenous QXC bore a modest amount of the antitumor agent. Noteworthy production of the biologically active molecule was achieved with small-scale cultivation and quantitative analysis of the product was accomplished with a liquid chromatography−mass spectrometer. This simple and speedy system could easily provide us with valuable information for maximizing the production titer. Our entirely heterologous production system also establishes a basis for the future use of E. colifor generation of novel bioactive compounds through tolerable precursor-directed biosynthesis. [ABSTRACT FROM AUTHOR]

The complex dielectric properties of CoTiO3 ceramics were investigated as functions of temperature (130 K [?] T [?] 430 K) and frequency (100 Hz [?] f [?] 100 kHz). Two thermally activated dielectric relaxations were observed. TiO2 addition and annealing treatments were used to modify the behaviour of these relaxations. It was found that the low-temperature relaxation can be greatly enhanced by the addition of TiO2. Annealing in N2 at 800 °C for 2 h eliminates the low-temperature relaxation but largely strengthens the high-temperature relaxation, whereas annealing in O2 at 800 °C for 2 h causes the opposite effects. It was suggested that the low-temperature relaxation can be related to the dipolar effect induced by charge-carrier hopping motions while the high-temperature relaxation might be ascribed to the defect dipolar polarization. [ABSTRACT FROM AUTHOR]

We describe the effects of magnetostatic interactions and film thickness on the switching properties and reversal mechanisms of periodic arrays of elongated Ni80Fe20 thin film rings. The magnetization reversal process, the switching field distributions and the transition fields between different equilibrium states are strongly affected by the inter-ring spacing. For closely packed ring arrays, sharp transitions were observed from the onion-to-vortex state due to collective magnetization reversal of the rings. In agreement with micromagnetic simulations, the range of stability of the vortex state is smaller for closely packed ring arrays compared with isolated rings of similar lateral dimensions. [ABSTRACT FROM AUTHOR]

Charge trapping characteristics of high-relative permittivity (high-?) HfO2films with Al2O3as a blocking oxide in p-Si/SiO2/HfO2/Al2O3/metal memory structures have been investigated. All high-? films have been grown by atomic layer deposition. A transmission electron microscope image shows that the HfO2film is polycrystalline, while the Al2O3film is partially crystalline after a high temperature annealing treatment at 1000 °C for 10 s in N2ambient. A well-behaved counter-clockwise capacitance-voltage hysteresis has been observed for all memory capacitors. A large memory window of ?7.4 V and a high charge trapping density of ?1.1 × 1013cm?2have been observed for high-? HfO2charge trapping memory capacitors. The memory window and charge trapping density can be increased with increasing thickness of the HfO2film. The charge loss can be decreased using a thick trapping layer or thick tunnelling oxide. A high work function metal gate electrode shows low charge loss and large memory window after 10 years of retention. High-? HfO2memory devices with high-? Al2O3as a blocking oxide and a high work function metal gate can be used in future high-density non-volatile memory device applications. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study was designed to establish human embryonic stem cell (hESC) lines, to identify the differences when maintained in serum-containing versus serum-free medium and to test their potential of in vitro differentiation. METHODS: Procedures including immunosurgery were performed on 11 donated human blastocysts to establish hESC lines. The cell lines were characterized and maintained using either serum-free or serum-containing media to compare their morphology, Oct-4 expression, apoptosis and growth speed. Differentiation of these lines was evaluated by the morphology and the expression of genes belonging to the three embryonic germ layers and the germ cell lineage. RESULTS: Three hESC lines were established, and they grew at similar speed in both media (serum-containing or serum-free), but hESC cultured in serum-containing medium yielded significantly higher percentages of morphologically good colonies and cells expressing Oct-4. These cell lines differentiated spontaneously in vitro into cells expressing markers belonging to all three embryonic germ layers and germ cell markers, including c-Kit, STELLA, VASA and growth differentiation factor 9 (GDF9), in directly adherent culture. CONCLUSIONS: Three hESC lines with Taiwanese ancestry have been established, and they retain the in vitro differentiation potential with or without embryoid body (EB) formation. The data support that hESC may be capable of differentiation into germ cells although further confirmation is needed. It is also suggested that strategies such as stepwise adaptation will be needed before implementing a serum-free culture condition for hESC lines that have previously been derived in a medium containing serum. [ABSTRACT FROM AUTHOR]

The photostability of thiol-capped CdTe quantum dots (QDs) in Euglena gracilis (EG277)and human embryonic kidney (HEK293) cells was studied. The photobleaching for thecellular QDs is dependent both on the irradiation power density and the QD localconcentration. The photostability of cellular QDs is better than that of chlorophyll inEG277 cells and of green fluorescence protein (GFP) in HEK293 cells, and is much betterthan that of FITC when the local concentration of QDs is not too low. The photobleachingof cellular QDs was remarkably reduced in the nitrogen treated EG277 cells,indicating that photobleaching in living cells mainly results from photo-oxidation.The effect of photo-oxidation on QDphotobleaching was further confirmed bycomparing the situations in oxygen treated and nitrogen treated QD aqueoussolutions. The photobleaching rate is related to the irradiation power densityand the local density of QDs. The higher irradiation power density and oxygenabundance and lower QDconcentration will result in a higher photobleaching rate. [ABSTRACT FROM AUTHOR]