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Abstract Open class is a public-oriented pedagogical practice aimed at enhancing teachers’ professional learning in China. This study examines how teachers conduct the open class and explores how open class facilitates the professional development of teachers. Through fieldwork at Sailing School and semi-structured interviews with nineteen teachers, four distinct phases of participation were identified: beginning (preparation for a show), presentation (using performance strategies), ending (evaluating teachers’ performance), and teamwork (cooperating with peers and students). Open class fosters four key forms of professional learning: enhancing the ability of instructional design, developing PCK in practice, fostering a pedagogical tact, and improving theoretical skills. The findings underscore open class as a platform to bridge the gap between practice and theory, while also highlighting a shift in teacher values from individualism to collectivism in open classes.

The power system stands as a crucial infrastructure pivotal to the country's modern economic, security and social development. This paper addresses challenges in insulator fault detection on power transmission towers, leveraging the advancements in unmanned aerial vehicles equipped with target detection methods. We propose a novel method for insulator defect detection based on YOLOv5 (You Only Look Once), aiming to mitigate the issues associated with high missed detection rates. Small insulator faults and the limitation of unmanned aerial vehicle on-board capacity make it difficult to detect comprehensively. Firstly, the cluster analysis was carried out on the training data to obtain 9 kinds of better preset anchors for insulator detection, which improved the accuracy of the model to identify the location of targets. Secondly, the base-model is used to detect the insulator region, and the detection results are input into the sub-model to detect the location of faults, so as to form a cascade model, and make full use of the advantages of the two models to solve the problem of high missed detection rate. Finally, a lightweight attention module combining channel attention module and spatial attention module is added in YOLOv5 to improve the base-model's attention to insulator region and suppress complex background features. Experimental results show that compared with the original model, the average precision of the proposed method for insulator detection is increased by 6.9%, and the missed detection rate of the fault location is 30% lower. Significant improvements in insulator detection performance have been achieved using the method proposed in this paper. It can not only effectively improve the detection accuracy, but also make the missed detection rate lower to meet the requirements of insulator defect detection and fault warning applications in complex environments, which proves that it has a wide range of application prospects in practice, especially in the field of power industry. [ABSTRACT FROM AUTHOR]

This research investigates the relationships between CO2 emissions, the economy, renewable energy consumption, green financing, and foreign direct investment in BRICS nations from 2000 to 2019 under the effect of higher education. The stationarity of the data was evaluated using three unit root tests: ADF-Fisher, Levin, Lin, and Chin and Im, Pesaran, and Shin. The panel autoregressive distributed lag approach identified the long-run and short-run elasticities. The empirical findings demonstrate that variables cointegrate. In the long run, renewable energy, economic growth, green finance, foreign direct investment, and higher education all influence CO2 emissions; however, in the short run, only economic growth, renewable energy, and higher education influence CO2 emissions. The findings also indicate that higher education increases dramatically at the individual and societal levels, reducing CO2 emissions in the short and long term. The overall empirical study of group and economy is supported by the results of robust statistics. In light of the results, the BRICS economies are advised to collaborate for sustainable growth while preserving environmental quality. Moreover, the BRICS countries should prioritize investing in the growth of higher education and enhancing the use of renewable energy for sustainable development. [ABSTRACT FROM AUTHOR]

Purpose: Rotating components such as rotating beams and plates are working in complex physical environments subjected to nonuniform distribution of their own materials, vibration caused by external excitation may result in work instability, structural fatigue and the like, so the dynamic analysis of rotating structures is of great significance. Methods: Based on the nonlocal elasticity theory and Timoshenko beam model, the vibration of a rotating functionally graded piezoelectric nanobeam is investigated. First, the dynamic governing equations and corresponding boundary conditions are derived by the Hamiltonian principle. Then, the governing equations and boundary conditions are discretized by the differential quadrature method. Subsequently, the vibration characteristics of nanobeams are analyzed after detailed numerical calculations. Results: The effects of various parameters including rotational velocity, nonlocal parameter, functional gradient index, length–height geometry ratio and external voltage on the vibration characteristics under different boundary conditions are examined. Finally, the numerical results show that these parameters have non-negligible effects on the natural frequencies and modal shapes. Conclusions: The dynamics of rotating functionally graded nanobeams are affected by both external kinematic and voltage factors and inherent scale factor and their coupling effects. In particular, a nonlinear small-scale effect is observed for a rotating functionally graded piezoelectric nanobeam, which may be useful to the design and optimization of the nano-electro-mechanical system including the rotating structures. [ABSTRACT FROM AUTHOR]

This paper presents a practicable regional division and cut algorithm for minimizing the sum of linear fractional functions over a polyhedron. In the algorithm, by using an equivalent problem (P) of the original problem, the proposed division operation generalizes the usual standard bisection, and the deleting and reduction operations can cut away a large part of the current investigated region in which the global optimal solution of (P) does not exist. The main computation involves solving a sequence of univariate equations with strict monotonicity. The proposed algorithm is convergent to the global minimum through the successive refinement of the solutions of a series of univariate equations. Numerical results are given to show the feasibility and effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]

Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme involved in folate metabolism and DNA synthesis. A number of studies have examined the association of MTHFR C677T and A1298C polymorphisms with non-Hodgkin lymphoma (NHL) susceptibility; however, the conclusions were contradictory. We searched available publications assessing the polymorphisms of MTHFR and NHL susceptibility from MEDLINE, EMBASE and CBM. Genotype-based mRNA expression analysis was performed using data from 270 individuals with three different ethnicities. Ultimately, a total of 7448 cases and 11146 controls from 25 studies were included for the C677T polymorphism, 6173 cases and 9725 controls from 19 studies for the A1298C polymorphism. Pooled results indicated that neither C677T nor A1298C polymorphism was associated with NHL susceptibility. However, C677T polymorphism showed a statistically significantly increased risk for Caucasians, but a decreased risk for Asians in the subgroup analysis by ethnicity. The same variants may confer increased susceptibility to develop follicular lymphoma (FL). Moreover, A1298C polymorphism was associated with increased NHL risk for Asians. This meta-analysis indicated that C677T polymorphism was associated with altered NHL susceptibility for Caucasians, Asians and FL. Increased NHL risk was also shown for A1298C among Asians. These findings warrant validation in large and well-designed prospective studies. [ABSTRACT FROM AUTHOR]

Low-cost quasi-solid-state dye-sensitized solar cells (DSSCs) are designed and fabricated by using a metal-free organic dye and a mesoporous carbon aerogel instead of expensive ruthenium-based sensitizers and Pt electrode. The electrospun TiO2 nanorods are added into a polyvinylidene fluoride (PVDF) solution to form a 3D network nanocomposite gel electrolyte. The presence of TiO2 nanorods in the gel electrolyte obviously increases the ionic conductivity and decreases charge-transfer resistance of the DSSC. The effects of the gel electrolyte and the carbon aerogel counter electrode on electrochemical and photovoltaic properties have been investigated in detail. Particularly, an optimized DSSC with a nanocomposite gel electrolyte and a carbon aerogel counter electrode affords a power conversion efficiency (PCE) of 6.20% at a light intensity of 100 mW cm-2. [ABSTRACT FROM AUTHOR]

The characteristic wetting behavior and modes of the evaporating Mg drops on the α-Al2O3 surfaces were evaluated by a combination of the variations in contact angle and drop geometry using both improved and modified sessile drop methods. The system is essentially partial wetting at 973 to 1173 K with initial contact angles of 94 to 67 deg, decreasing with increasing temperature. The wettability improves with interfacial reaction but deteriorates with Mg surface oxidation. The presence of the oxide film at the Mg drop surface strongly inhibits the movement of the triple line and thus makes the constant contact diameter mode dominate the entire wetting process. Removal of the oxide film greatly facilitates the depinning of the triple line. On the other hand, the interfacial reaction leads to the prior formation of MgO and later MgAl2O4 as a result of consumption of Mg, while it increases the amount of displaced Al. Nevertheless, the role of the interfacial reaction on the wetting is difficult to quantitatively evaluate because of concurrent diminishing in the drop volume under evaporation. [ABSTRACT FROM AUTHOR]

A two dimensional wind sensor was designed, fabricated and packaged on ceramic substrate instead of silicon substrate. The Ti/Pt heater and thermistors were fabricated using single lift-off process. The gold bumps were then sputtered and patterned on the chip using lift-off process again. Correspondingly, the Pb/Sn bumps were fabricated on the FR4 substrate using stencil printing method after metallization. The sensor chip was flip-chip packaged on the FR4 substrate, and the gap was filled with epoxy-based underfill to improve the structure strength. The packaged sensor was tested in wind tunnel in constant power mode. The wind velocity and direction offsets of the sensor were compensated using software and hardware calibration. Both the simulation and test results show that the thermal wind sensor can measure wind speeds up to 8 m/s with an accuracy of 0.3 m/s, and wind direction in a full range of 360° with a resolution within 5°. [ABSTRACT FROM AUTHOR]

The wetting behaviors of molten Mg drops on polycrystalline ZrO2 substrate surfaces were studied in a controlled Ar atmosphere at 948–1173 K using an improved sessile drop method. The ZrO2 substrate is virtually not wetted by molten Mg at temperatures below 1173 K. The wetting and evaporation stages according to different variation behaviors of contact angle, contact diameter and drop height were identified. Six representative modes were proposed to describe the evaporation-coupled wetting behaviors during different stages. The competitions between surface oxidation, chemical reaction and drop evaporation were discussed to account for the mechanisms for various wetting behaviors at different temperatures. The chemical reaction leads to the formation of more wettable MgO phase at the interface; however, it yields only an inconspicuous improvement in the wetting due to enhanced Mg evaporation. [ABSTRACT FROM AUTHOR]

This paper investigates the multiaxial fatigue life of the roller in rolling contact with wheels with respect to axis line deflection. The multiaxial fatigue criteria proposed by Wang and Brown, together with the rainflow counting method and Miner-Palmgren’s rule, are applied to the cumulative damage estimation and life prediction. As the axis line deflection of overlong kilns generally results in asymmetric load distribution on each roller, the load ratio is introduced to describe the deflection for quantitative stress analyses. The stress analyses are performed within the finite element code ANSYS. The tangential friction stress is calculated in terms of the condition of the rolling contact area. By taking one roller as an example, the plotted fatigue life versus load ratio curve discovers how the axis line deflection affects the fatigue life. This study is significant to prevent the fatigue failure of the roller and can provide basis to adjust and optimize the axis line of the rotary kiln. [ABSTRACT FROM AUTHOR]

Bacillus subtilis spore preparations are promising probiotics and biocontrol agents, which can be used in plants, animals, and humans. The aim of this work was to optimize the nutritional conditions using a statistical approach for the production of B. subtilis (WHK-Z12) spores. Our preliminary experiments show that corn starch, corn flour, and wheat bran were the best carbon sources. Using Plackett–Burman design, corn steep liquor, soybean flour, and yeast extract were found to be the best nitrogen source ingredients for enhancing spore production and were studied for further optimization using central composite design. The key medium components in our optimization medium were 16.18 g/l of corn steep liquor, 17.53 g/l of soybean flour, and 8.14 g/l of yeast extract. The improved medium produced spores as high as $$ 1.52 \pm 0.06 \times {10^{10}}{\text{spores}}/{\text{ml}} $$ under flask cultivation conditions, and $$ 1.56 \pm 0.07 \times {10^{10}}{\text{spores}}/{\text{ml}} $$ could be achieved in a 30-l fermenter after 40 h of cultivation. To the best of our knowledge, these results compared favorably to the documented spore yields produced by B. subtilis strains. [ABSTRACT FROM AUTHOR]

Although ubiquitous in all haloarchaea, little is known about the transcription and regulation of the haloarchaeal hsp70. The purpose of this study is to investigate the transcription of the haloarchaeal hsp70 gene in Natrinema sp . J7 under the temperature and osmotic stress. The hsp70 gene was found to be both temperature- and osmotic-induced, while the response of hsp70 to cold shock was stronger than that to heat shock. Western blot analysis corroborated the similar results at the level of Hsp70 protein. Northern blot and primer extension analyses indicated that the hsp70 was transcribed into a monocistronic transcript and the thermal stress had no effect on the transcription initiation sites choice. The deletion analyses showed that two putative elements, TATA-box (TTTAAAA) and BRE (AGTAAC) located −27 bp upstream of the transcription initiation site played an essential role for the basal transcription of P hsp70. The results suggested that there are some special regulators of hsp70 gene in Natrinema sp. J7. [ABSTRACT FROM AUTHOR]

Abstract  A system-level model with lumped parameters for a thermal flow sensor is presented. The model is built with 13 circuit cells consisting of thermal resistors and thermal capacitors in SPICE. The circuit cell originates from the heat conduction equation using the Finite Differential Method, including the 2-D thermal conduction cell, the convection cell, and the thermal capacity in the chip. Based on the thermal model of the flow sensor, the 2-D temperature distribution of the chip can be calculated with SPICE in both the constant power mode (CP) and constant temperature difference mode (CTD). As an example, the system level model of the thermal anemometer in the CTD mode was established in PSPICE. Wind tunnel test was carried out to verify the system model, and show a reasonable agreement with the simulation results, with an error less than 8%. [ABSTRACT FROM AUTHOR]

The wetting behaviors of molten Zr55Cu30Al10Ni5 metallic glass alloy on polycrystalline α-Al2O3 substrates were investigated using a modified sessile drop method at 1133 to 1193 K in vacuum. Excellent wettability with final contact angles approaching zero degree and mild interfacial reaction were observed. The spreading followed a well-defined exponential decay law. It is the Zr adsorption at the interface and then formation of a Zr-Cu precursor film rather than the interfacial reaction that accounts for the excellent wettability in this system. [ABSTRACT FROM AUTHOR]

Abstract  The present study was undertaken to evaluate whether estrogen deprivation might lead to mitochondrial alteration of hippocampal neurons of ovariectomized (OVX) rats, and to evaluate the protective effect of estrogen and phytoestrogen on the mitochondrial alteration. First, OVX rats were used to mimic the pathologic changes of neurodegeneration of postmenopausal female, and we looked into the alteration of the mitochondrial ultrastructure and ATP content of hippocampal CA1 region after ovariectomy on different phase by transmission electron microscope (TEM) and reversed-phase high-performance liquid chromatography (HPLC), and found the best phase points of the alteration of the mitochondrial ultrastructure and ATP content. Next, estrogen and phytoestrogen were administered to the OVX rats for the protective effects on the mitochondrial ultrastructure and ATP content. Meanwhile, the density, size, shape, and distribution parameters of mitochondrial ultrastructure were analyzed according to the morphometry principle. The experimental results presented that (1) The alteration of mitochondrial ultrastructure elicited by ovariectomy worsened with the days going on, and the changes were the most noteworthy in volume density (Vv), average surface area (S), specific surface area (δ), and particle dispersity (Cλz) on 12th day (P P P P P  [ABSTRACT FROM AUTHOR]

The reaction behavior and mechanism during self-propagating high-temperature synthesis (SHS) in an Al-TiO2-B4C system were investigated. The result shows that the reaction could be self-sustaining for the Al content no more than 58.4 wt pct in the reactants. With the increase in Al, the combustion temperature decreases monotonically, the ignition delay time first decreases and then increases, while the combustion wave velocity displays an opposite behavior. The reaction mechanisms are somewhat dependent on the Al content, while the resultant types of the final products are independent. The desired reaction products make the Al-TiO2-B4C system ideal for producing the ( α-Al2O3-TiC-TiB2)/Al composites using the SHS technique. [ABSTRACT FROM AUTHOR]

Abstract  Integrated geological and geophysical investigations were carried out in 26 active mines in Northwestern China during the period 2001–2006 to explore for hidden extensions of known ore bodies and to search for new mineralization. This paper presents four case studies from northwest China: the Kuoerzhenkuoa volcanogenic hydrothermal gold deposit, the Nanjinshan breccia-associated gold deposit, the Duolanasayi deposit, associated with a ductile–shear zone, and the Hulu magmatic Cu–Ni sulfide deposit. In these studies, detailed mine-scale geological studies were carried out to determine the location and controls on ore formation. Based on these investigations and a review of previous exploration data, genetic models for the deposits were evaluated, and specific new targets were generated. These target areas were tested with surface geophysical surveys using the Stratagem EH4 system, a hybrid-source magnetotellurics (MT) method. Analysis of the data obtained in the surveys identified geophysical target anomalies that were subsequently drilled. Many of these test holes demonstrate the presence of Au and Cu–Ni mineralization. Evaluation of the geological models was crucial in developing conceptual targets as a basis for surface geophysical surveys. These models established the most likely target areas where Au and Cu–Ni mineralization could occur, but they did not define the limits or the geometries of the mineralized zones. Hybrid MT surveys played an important role in defining the location of buried mineralized systems and in testing the validity of the conceptual targets. The resistivity cross-sections obtained by imaging the MT data established the boundaries and geometries of the host rocks, including the distribution of lithology, structures, alteration, and mineralization. The four case studies in this paper show how this integrated geological and geophysical approach was used successfully to discover hidden mineral deposits. [ABSTRACT FROM AUTHOR]

Drosophila melanogaster postfeeding larvae show food-averse migration toward food-free habitats before metamorphosis. This developmental switching from food attraction to aversion is regulated by a neuropeptide Y (NPY)-related brain signaling peptide. We used the fly larva model to delineate the neurobiological basis of age-restricted response to environmental stimuli. Here we provide evidence for a fructose-responsive chemosensory pathway that modulates food-averse migratory and social behaviors. We found that fructose potently elicited larval food-averse behaviors, and painless (pain), a transient receptor potential channel that is responsive to noxious stimuli, was required for the fructose response. A subset of pain-expressing sensory neurons have been identified that show pain-dependent excitation by fructose. Although evolutionarily conserved avoidance mechanisms are widely appreciated for their roles in stress coping and survival, their biological importance in animal physiology and development remains unknown. Our findings demonstrate how an avoidance mechanism is recruited to facilitate animal development. [ABSTRACT FROM AUTHOR]

Well-aligned Co3O4 nanotubes were synthesized within the nanochannels of porous anodic alumina membranes using a single-source chemical vapor deposition method. Scanning electron microscopy and transmission electron microscopy showed that the Co3O4 nanotubes are highly ordered with uniform diameter in the range of 100–300 nm and length up to tens of microns. X-ray diffraction, the Raman spectrum, energy-dispersive spectroscopy and selected-area electron diffraction demonstrated that the nanotubes are composed of pure cubic phase polycrystalline Co3O4. Magnetic measurements using a SQUID magnetometer suggested the presence of a strong antiferromagnetic interaction with Weiss constant θ= -248 K. The real and imaginary parts of the ac susceptibility at f= 10 Hz had a maximum at 4.0 K, and the field dependence of the magnetization at 1.8 K showed a small hysteresis loop with a coercivity of ∼ 98 Oe. [ABSTRACT FROM AUTHOR]

Abstract  Self-assembly of the precursor [Cu(L)]2 (L = 3,10-dipropyl-1,3,5,8,10,12-hexaazacyclotetradecane) with hexacyanometalate [Fe(CN)6]3− produces a 3-D cyano-bridged Cu(II)–Fe(III) bimetallic assembly, [CuL]2[Fe(CN)6]ClO4 · H2O (1), characterized by single-crystal X-ray diffraction studies, and magnetic measurements. The crystallographic determination reveals that each hexacyanoferromate(III) ion connects four copper(II) ions using four co-planar CN− groups which axially coordinate to the copper ion in a trans fashion forming trans-CuL(N≡C)2 moieties in (1). Magnetic studies reveal that (1) displays a ferromagnetic interaction between Cu(II) and Fe(III) through the CN linkage. [ABSTRACT FROM AUTHOR]

Abstract  A microcalorimeric technique was used to evaluate the influence of rare earths Ce3 on Halobacterium halobium R1 growth. By means of TAM air Thermal Activity Monitor, the thermogenic curves of H. halobium R1 growth were obtained. To analyze the results, the growth rate constant k and IC50 were calculated, indicating that the values of k are linked to the concentration of Ce3. The growth rate constant k of H. halobium R1 decreased gradually in the low concentration; thus, rare earths restrained the growth of H. halobium R1. On the contrary, as the concentration of Ce3 became higher, the value of k for H. halobium R1 increased gradually, which showed Ce3 stimulated the growth of H. halobium R1. When the concentration of rare earths became much higher, the value of k for H. halobium R1 also decreased, and the growth of H. halobium R1 was restrained totally in the end. By using transmission electron microscopy (TEM), it was observed that the transforming of H. halobium R1 in the different concentrations of Ce3 confirmed the results derived from microcalorimetry. According to the thermogenic curves and TEM photos of H. halobium R1 under various conditions, it showed that there was some special effect about the interaction between rare earths and H. halobium R1 growth. [ABSTRACT FROM AUTHOR]

The TiC–TiB2/Al composites were fabricated by self-propagating high-temperature synthesis (SHS) from Al–Ti–B4C compacts. The addition of Al to the Ti–B4C reactants facilitates the ignition occurrence, lowers the reaction exothermicity, and modifies the resultant microstructure. The maximum combustion temperature and combustion wave velocity decrease with the increase in the Al amount. The B4C particle size exerts a significant effect on the combustion wave velocity and the extent of the reaction, while that of Ti has only a limited influence. The reaction products are primarily dependent on the B4C particle size and the Al content in the reactants. Desired products consisting of only the TiC, TiB2, and Al phases could be obtained by a cooperative control of the B4C particle size and the Al content. [ABSTRACT FROM AUTHOR]

Steel matrix composites locally reinforced by in situ TiC and TiB2 particulates were successfully fabricated using self-propagating high-temperature synthesis (SHS) in a Fe–Ti–B4C–C system during casting. The locally reinforced steel matrix composites consist of three distinct regions: (i) a TiC and TiB2 particulate-reinforced region, (ii) a transition region, and (iii) a steel matrix region. The TiC and TiB2 particulates in the locally reinforced regions display a relatively uniform distribution, and their sizes decrease with the increase in Fe content from 10 wt.% to 40 wt.%. The wear resistance of the locally reinforced region of the steel matrix composites is much higher than that of the unreinforced steel matrix. [ABSTRACT FROM AUTHOR]

Abstract  In this paper, it is shown that stable model semantics, perfect model semantics, and partial stable model semantics of disjunctive logic programs have the same expressive power with respect to the polynomial-time model-equivalent reduction. That is, taking perfect model semantics and stable model semantic as an example, any logic program P can be transformed in polynomial time to another logic program P′ such that perfect models (resp. stable models) of P 1-1 correspond to stable models (resp. perfect models) of P′, and the correspondence can be computed also in polynomial time. However, the minimal model semantics has weaker expressiveness than other mentioned semantics, otherwise, the polynomial hierarchy would collapse to NP. [ABSTRACT FROM AUTHOR]

Abstract  Marek’s forward-chaining construction is one of the important techniques for investigating the non-monotonic reasoning. By introduction of consistency property over a logic program, they proposed a class of logic programs, FC-normal programs, each of which has at least one stable model. However, it is not clear how to choose one appropriate consistency property for deciding whether or not a logic program is FC-normal. In this paper, we firstly discover that, for any finite logic program Π, there exists the least consistency property LCon (Π) over Π, which just depends on Π itself, such that, Π is FC-normal if and only if Π is FC-normal with respect to (w.r.t.) LCon (Π). Actually, in order to determine the FC-normality of a logic program, it is sufficient to check the monotonic closed sets in LCon (Π) for all non-monotonic rules, that is LFC (Π). Secondly, we present an algorithm for computing LFC (Π). Finally, we reveal that the brave reasoning task and cautious reasoning task for FC-normal logic programs are of the same difficulty as that of normal logic programs. [ABSTRACT FROM AUTHOR]

The results presented in this article show that direct plasmid transfer from Escherichia coli carrying shuttle plasmid to Bacillus subtilis occurred when close contact between the two species was established by mixing E. coli and B. subtilis onto selective agar plates. The data demonstrate that the production of resistant colonies by plasmid transformation through cell contact was DNase I sensitive and dependent on transformable B. subtilis strains. Furthermore, another observation indicated that the E. coli strain is able to affect the transformation capability of B. subtilis. It is assumed that the donor strain is a momentous factor for taking up plasmid DNA. This conclusion is significant in the assessment of both the possibility of intercellular DNA transfer in natural habitats of micro-organisms and the risk of the application of genetically engineered micro-organisms. [ABSTRACT FROM AUTHOR]

Reactive wetting of hexagonal BN by molten Al at 1073–1273 K was studied using an improved sessile drop method. The temperature and substrate surface roughness have a remarkable effect on the wetting behavior. Reasons for the large discrepancy in the final contact angles reported in the literature were addressed. [ABSTRACT FROM AUTHOR]

Natural IgM can recognize apoptotic cells, but the molecular structure and the role in macrophage phagocytosis of apoptotic cells remain unclear. Objectives(1) To examine the binding of previously isolated natural IgM (3B4) to apoptotic cells and its effects on phagocytosis of apoptotic cells. (2) To characterize the molecular structure of 3B4. Methods:3B4 binding to apoptotic thymocytes was examined by flow cytometry. Polyreactivity of 3B4 was assayed by ELISA. PKH26-labeled Macrophages were incubated with PKH67-stained apoptotic cells in the presence of 3B4. Macrophages phagocytosis of apoptotic cell was evaluated by flow cytometry. The DNA segments of 3B VH and VK were sequenced and analyzed. Results:3B4 IgM recognized late apoptotic cells. Polyreactive-recognitions of lysophosphatidylcholine (LPC) as well as some autoantigens were observed in 3B4. Phagocytosis of late apoptotic cells was increased in the presence of 3B4. The VH and VK genes of 3B4 showed a germline gene context, while N-sequences and nucleotide loss were observed in CDR3. Conclusion: 3B4 promotes macrophage phagocytosis of late apoptotic cells in a complement-independent process. 3B4 has a germline configuration and is possibly ligand-selected. Out experiments suggest an independent role of natural IgM as opsonin in clearance of late apoptotic cells. [ABSTRACT FROM AUTHOR]

A gene encoding an extracellular protease, sptA, was cloned from the halophilic archaeon Natrinema sp. J7. It encoded a polypeptide of 565 amino acids containing a putative 49-amino acid signal peptide, a 103-amino acid propeptide, as well as a mature region and C-terminal extension, with a high proportion of acidic amino acid residues. The sptA gene was expressed in Haloferax volcanii WFD11, and the recombinant enzyme could be secreted into the medium as an active mature form. The N-terminal amino acid sequencing and MALDI-TOF mass spectrometry analysis of the purified SptA protease indicated that the 152-amino acid prepropeptide was cleaved and the C-terminal extension was not processed after secretion. The SptA protease was optimally active at 50°C in 2.5 M NaCl at pH 8.0. The NaCl removed enzyme retained 20% of its activity, and 60% of the activity could be restored by reintroducing 2.5 M NaCl into the NaCl removed enzyme. When the twin-arginine motif in the signal peptide of SptA protease was replaced with a twin-lysine motif, the enzyme was not exported from Hfx. volcanii WFD11, suggesting that the SptA protease was a Tat-dependent substrate. [ABSTRACT FROM AUTHOR]

The wetting behaviors of $$\hbox{R}(01\bar{1}2)$$ single crystalline and polycrystalline $$\alpha\hbox{-}\hbox{Al}_{2}\hbox{O}_{3}$$ substrates by Al–Si alloys were studied over wide composition and temperature ranges. The wettability is quite good for all compositions of the alloys. The effect of temperature is moderate while that of the composition is significant. The dependence of the wettability on the alloy composition displays a “valley” profile with the minimum value appearing in the range of 60–70at.%Si. The wetting improvement by the addition of Al to Si mainly results from the decrease in the solid–liquid interfacial free energy by the Al segregation at the interface, while that by the addition of Si to Al results from the decrease in the surface tension of the liquid by the Si segregation. [ABSTRACT FROM AUTHOR]

The oxygen-evolving complex (OEC) of Mn-depleted photosystem II (PSII) can be reconstituted in the presence of exogenous Mn or a Mn complex under weak illumination, a process called photoactivation. Synthetic Mn complexes could provide a powerful system to analyze the assembly of the OEC. In this work, four mononuclear Mn complexes, [(terpy)2MnII(OOCH3)]·2H2O (where terpy is 2,2′:6′,2″-terpyridine), MnII(bzimpy)2, MnII(bp)2(CH3CH2OH)2 [where bzimpy is 2,6-bis(2-benzimidazol-2-yl)pyridine] and [MnIII(HL)(L)(py)(CH3OH)]CH3OH (where py is pyridine) were used in photoactivation experiments. Measurements of the photoreduction of 2,6-dichorophenolindophenol and oxygen evolution demonstrate that photoactivation is more efficient when Mn complexes are used instead of MnCl2 in reconstructed PSII preparations. The most efficient recoveries of oxygen evolution and electron transport activities are obtained from a complex, [MnIII(HL)(L)(py)(CH3OH)]CH3OH, that contains both imidazole and phenol groups. Its recovery of the rate of oxygen evolution is as high as 79% even in the absence of the 33-kDa peptide. The imidazole ligands of the Mn complex probably accelerate P reduction and consequently facilitate the process of photoactivation. Also, the strong intermolecular hydrogen bond probably facilitates interaction with the Mn-depleted PSII via reorganization of the hydrogen-bonding network, and therefore promotes the recovery of oxygen evolution and electron transport activities. [ABSTRACT FROM AUTHOR]

Signal extraction from overlapping seismic records is a common problem in geophysical data analysis. Identification and separation of multiple seismic arrivals, analysis of large earthquakes as multiple point sources, and calculation of the true yield of a large nuclear explosion from interfering small explosion, all hinge on our ability to effectively decouple two interfering wave signals. This paper presents a method for signal separation based on an adaptive filtering technique. We apply a semi-deconvolution algorithm to overlapping explosion records and S/SKS phase groups, and then perform noise reduction and signal decoupling under different a priori conditions and assess the stabilities using a variance reduction approach. We demonstrate, through numerical experiments and analysis of seismic station records, that the adaptive method can be both robust and practical for regional and teleseismic applications. [ABSTRACT FROM AUTHOR]

This paper analyzes the precision of the dissymmetrical parallel mechanism of 3-RRRP(4R) with three translational degrees of freedom (DOF). The parallel mechanism has weakly-coupled, decoupled and real-time characteristics, thus error compensation can be done using control software. Based on topology structure analysis, the inverse and forward solutions are analyzed and the precision is studied using complete differential method. The influencing factors of the manipulator’s precision are studied carefully and the means to enhance the precision are also discussed. It is found that the position errors of the moving platform have nonlinear relation with the position of the mechanism. The δθ’3 error has the biggest influence on the nonlinear errors of the position. Otherwise, the original errors of the mechanism are the main reason leading to more errors. Thus enhancing machining and assembling precision is an important method to enhance the precision of the mechanism. [ABSTRACT FROM AUTHOR]

Omnivores, including humans, have an inborn tendency to avoid noxious or unfamiliar foods. Such defensive foraging behaviors are modifiable, however, in response to physiological needs. Here we describe a method for assessing risk-sensitive food acquisition in Drosophila melanogaster. Food-deprived fly larvae become more likely to feed on noxious foods (adulterated with quinine) as the duration of deprivation increases. The neuropeptide F receptor NPFR1, a mammalian neuropeptide Y (NPY) receptor homolog, centrally regulates the response to noxious food in D. melanogaster. Overexpression of NPFR1 was sufficient to cause nondeprived larvae to more readily take in noxious food, whereas loss of NPFR1 signaling led to the opposite phenotype. Moreover, NPFR1 neuronal activity may be directly regulated by the insulin-like signaling pathway. Upregulation of insulin-like receptor signaling in NPFR1 cells suppressed the feeding response to noxious food. Our results suggest that the coordinated activities of the conserved NPY- and insulin-like receptor signaling systems are essential for the dynamic regulation of noxious food intake according to the animal's energy state. [ABSTRACT FROM AUTHOR]

To investigate the preventive and protective effects of bendazac lysine (BDL) on experimental early diabetic nephropathy (DN) rats.After an early DN model was induced by streptozotocin, rats were administered BDL at doses of 100, 200, and 400 mg/kg for 8 weeks. Blood glucose, microalbuminuria, kidney index, total antioxidative capacity, laminin, advanced glycation end products (AGE), aldose reductase (AR) activity, and the relative quantity of transforming growth factorβ1 (TGF-β1) mRNA were measured by different methods. The ultrastructural morphology was observed by transmission electron microscope.The physical behaviors of early DN rats were hypopraxia, cachexia, and polyuria, while those treated with high doses of BDL were vibrant and vigorous. For BDL-treated DN rats, when compared with vehicle-treated DN rats, the blood glucose level and the intensity of oxidative stress were ameliorated. Also, the micro albuminuria level, AGE either in serum or in renal, and AR activity were significantly reduced. Furthermore, the expression of TGF-β1 mRNAinthe kidney cortex was declined and the thickness of glomerular base membrane was decreased significantly. The ultrastructure of glomerulus and mesangial matrix of BDL-treated DN rats were ameliorated.BDL has protective effects on several pharmacological targets in the progress of DN and is a potential drug for the prevention of early DN. [ABSTRACT FROM AUTHOR]

The reactive wetting behavior of SiO2 substrates by molten Al was investigated at temperatures between 800°C to 1250°C in a purified Ar-3 pct H2 atmosphere of about 0.11 MPa using an improved sessile drop method. The time dependence of the changes in contact angle and droplet geometry was monitored and the wetting kinetics was identified. The initial equilibrium or quasi-equilibrium contact angles are generally larger than 90 deg and do not significantly vary with temperature. The subsequent remarkable decrease in the contact angle mainly results from the progressive decrease in the droplet volume rather than the advance of the solid-liquid interfacial front. The significant effect of temperature on the wetting kinetics is essentially related to its effect on the reaction and molten Al penetration progress. For systems with a considerable decrease in the droplet volume during reactive wetting, a criterion for evaluation of the true wetting improvement was proposed. [ABSTRACT FROM AUTHOR]

To study the mitochondrial DNA (mtDNA) polymorphisms in a total of 232 individuals from five ethnic populations (Daur, n=45; Ewenki, n=47; Korean, n=48; Mongolian, n=48; Oroqen, n=44) in northern China, we analyzed the control region sequences and typed for a number of characteristic mutations in coding regions (especially the region 14576–16047), by direct sequencing or restriction-fragment-length-polymorphism (RFLP) analysis. With the exception of 14 individuals belonging to the European-specific haplogroups R2, H, J, and T, the mtDNAs considered could be assigned into the East Asian-specific haplogroups described recently. The polymorphisms in cytochrome b sequence were found to be very informative for defining or supporting the haplogroups status of East Asian mtDNAs in addition to the reported regions 10171–10659 and 14055–14590 in our previous study. The haplogroup distribution frequencies varied in the five ethnic populations, but in general they all harbored a large amount of north-prevalent haplogroups, such as D, G, C, and Z, and thus were in agreement with their ethnohistory of northern origin. The two populations (Ewenki and Oroqen) with small population census also show concordant features in their matrilineal genetic structures, with lower genetic diversities observed. [ABSTRACT FROM AUTHOR]

The objective of this work is to study the effects of hydrothermal treatment conditions on the methylation of 4-methylbiphenyl (4-MBP) with methanol under fixed-bed down-flow conditions. The results show that hydrothermal treatment temperature has a marked effect on the activity and selectivity in the methylation of 4-MBP with methanol. 4-MBP conversion decreases and the selectivity to 4,4′-dimethylbiphenyl (4,4′-DMBP) increases with an increase in the hydrothermal treatment temperature. The optimal temperature range is between 400 and 550 °C. After hydrothermal treatment, the catalytic selectivity to 4,4′-DMBP is up to 70%, while the 4-MBP conversion is about 12%. The high selectivity over hydrothermally treated ZSM-5 largely results from the suppression of 4,4′-DMBP secondary reactions such as isomerization and dealkylation, as demonstrated by the reaction of 4,4′-DMBP as reactant over hydrothermally treated ZSM-5 and the parent zeolite. [ABSTRACT FROM AUTHOR]

Provides information on a study regarding biogenic gas and premature-low mature (PLM) associated gases in some medium and small-sized basins of Yanan Province in China. Sampling and analysis of gaseous samples; Discovery and theoretical study of PLM oil and the biothermocatalytic transitional zone gas; Conclusion.

The relative importance of local and regional sources of lead and associated elements in fine and coarse aerosol particles of an urban atmosphere was assessed by means of a two-day study, July 20 and 30, 1980 in Beijing, China. Five near-ground locations were selected for aerosol sampling by cascade impactors and elemental analysis by proton induced X-ray emission (PIXE): the imperial palace courtyard, a park, near two streets, and a mid-street traffic island. These sites, ranked in order of increasing traffic intensity and fugitive surface dust, showed that concentrations of major dust constitutents, represented by coarse particle (>2 μm diameter) Si, Al, and Ca, increased correspondingly. Pb, as well as Zn, As, and Cu, were present mainly in fine (<2 μm) particles; their concentrations were unrelated to traffic, indicating they resulted mainly from regional combustion or other sources. However, these elements also were present in coarse particles at concentrations that varied with the major dust elements and were relatively enriched, compared to average earth crust rock material, by factors of more than 100 (Pb), 50 (Zn), and 10 (Cu). Nonurban Beijing shows much smaller coarse aerosol enrichments of Pb, Zn, and Cu, indicating urban contamination of surface dust. Published data from St. Louis, USA show both fine and coarse aerosol Pb and Zn. Compared with Beijing, fine and coarse concentrations in St. Louis are similar for Pb, but lower for Zn, Ca, and Fe. Both Pb and Zn are enriched relative to earth crust composition to a greater degree in St. Louis than Beijing in both fine and coarse particle size ranges. The results suggest that heavy metals from combustion occur in the air as fine particles and, after deposition on the surface, as reentrained coarse particles of fugitive dust. Both many contribute to human exposures of these heavy metals. [ABSTRACT FROM AUTHOR]

Based on the first-hand information on the Zhongyuan-Huabei oil-gas area, this paper gives a description of the geochemical characteristics of the coal-type gas in this area. In terms of the carbon isotopic composition of methane, argon isotopic characteristics of natural gases, the carbon isotopic composition of condensate and the abundance of mercury in natural gases, the paper discusses the differences in chemical and isotopic compositions between the coal-type gas and the oil-type gas, and presents the indices for comprehensively distinguishing the coal-type gas from the oil-type gas. A systematic and scientific dissetation of some typical examples of gas reservoirs, such as the Wenliu, Suqiao and Shenze gas reservoirs, gives evidence suggesting that the gas reservoirs are of coal type. This indicates the existence of natural gas reservoirs of commercial value related to gas-source rocks of the Carboniferous-Permian coal series. This study provides important clues to the exploration and development of the coaltype gas reservoirs in China. [ABSTRACT FROM AUTHOR]

Presents information on a study pertaining to noble gas geochemistry while focusing on its importance in the geological processes such as genesis of natural gas in China. Objective of the study; Information on the experiments and results; Detailed information on the discussion.

Presents a case study which described an infant with Behçet disease who presented with chronic diarrhea and recurrent oral ulcers. Criteria of the disease; Results of physical examination; Symptoms of the disease.

Focuses on a study which analyzed the carbin isotope of the trace gas in an adsorbed gas from the oil sand bed of the Aican-1 Well in the southern part of the Turpan-Hami basin. Materials and experimental procedures; Discussion of results; Conclusions.