Effect of New O-Superfamily Conotoxin on Voltage-Activated Currents of Hippocampal Neurons

The effects of a new O-superfamily conotoxin, SO3, on sodium current (INa), transient A-type potassium currents (IA), and delayed rectified potassium currents (IK), were examined in cultured rat hippocampal neurons using the whole-cell patch clamp technique. Addition of SO3 caused a concentration-dependent, rapidly developing, and reversible inhibition of voltage-activated currents. The IC50 values for the blockage of INa, IA, and IK were calculated as 0.49, 33.9, and 7.6 μmol/L, respectively. The determined Hill coefficients were 1.7, 0.6, and 1.2, respectively. These results indicate that SO3 can selectively inhibit neuronal sodium and potassium currents.     

Nanoengineering of amino - functionalized mesoporous silica nanospheres as nanoreactors

Selective functionalization of mesoporous silica nanospheres (MSNs) is crucial for nanoengineering of MSNs. Herein, we have combined “surface-protected etching strategy” and “cationic surfactant assisted etching strategy” to prepare functionalized MSNs with externally attached amino groups. The externally attached NH2 groups endow the catalysts with excellent catalytic performance for nitroaldol reaction between nitromethane and benzaldehyde. In addition, those NH2-MSNs can also be used to support gold nanoparticles, which display very good catalytic performance for reduction of 4-nitrophenol. It can be envisioned that the synthesis protocol developed in this work could also be extended to nanoengineered MSNs, which provides opportunities for nanoreactors design.     

Dynamic Dominating Set and Turbo-Charging Greedy Heuristics

The main purpose of this paper is to exposit two very different, but very general, motivational schemes in the art of parameterization and a concrete example connecting them. We introduce a dynamic version of the DOMINATING SET problem and prove that it is fixed-parameter tractable（FPT）. The problem is motivated by settings where problem instances evolve. It also arises in the quest to improve a natural greedy heuristic for the DOMINATING SET problem.     

Studies on induction hardening of powder-metallurgy-processed Fe-Cr/Mo alloys

Induction hardening of dense Fe-Cr/Mo alloys processed via the powder-metallurgy route was studied. The Fe-3Cr-0.5Mo, Fe-1.5Cr-0.2Mo, and Fe-0.85Mo pre-alloyed powders were mixed with 0.4wt%, 0.6wt%, and 0.8wt% C and compacted at 500, 600, and 700 MPa, respectively. The compacts were sintered at 1473 K for 1 h and then cooled at 6 K/min. Ferrite with pearlite was mostly observed in the sintered alloys with 0.4wt% C, whereas a carbide network was also present in the alloys with 0.8wt% C. Graphite at prior particle boundaries led to deterioration of the mechanical properties of alloys with 0.8wt% C, whereas no significant induction hardening was achieved in alloys with 0.4wt% C. Among the investigated samples, alloys with 0.6wt% C exhibited the highest strength and ductility and were found to be suitable for induction hardening. The hardening was carried out at a frequency of 2.0 kHz for 2-3 s. A case depth of 2.5 mm was achieved while maintaining the bulk (interior) hardness of approximately HV 230. A martensitic structure was observed on the outer periphery of the samples. The hardness varied from HV 600 to HV 375 from the sample surface to the interior of the case hardened region. The best combination of properties and hardening depth was achieved in case of the Fe-1.5Cr-0.2Mo alloy with 0.6wt% C.     

Social Media as a Mean for Improved Technical Communication

Technical communication (TC) is an important activity in order to provide the users of technical artifacts with necessary information concerning the operation and maintenance of the products they are using. In the current working procedures of TC, however, the users become too passive. They are just receivers of information. Further, there is no effective feedback from the users to the producers of the information. In order to overcome those problems we here propose an application of social media (SM) in future TC. By using SM as a complementary channel for TC it becomes possible for technology firms to boost their competitive advantage and to improve the quality and completeness of their TC. This technique, however, is still more of a potential and less of a reality. Several problems, mostly concerning security and confidentiality remain to be solved. The empirical base for this work comes from TIC, an EU-funded development project involving several Swedish technology companies. Published research results are somewhat scattered but several sources coherently indicate both the need and potential for SM as a vehicle in TC. By scanning the net it is further possible to identify a number of seemingly successful applications of SM in such applications.     

Collaborative Project Management: A Systemic Approach to Heavy Equipment Manufacturing Project Management

Quite often over the last decade, heavy equipment manufacturers are trying to improve their project management performance with the use of effective project management methods. However, the challenges encountered aren’t isolated problems and a systemic approach is required. This paper exemplifies how a systemic approach can be applied to heavy equipment manufacturing project (HEMP) management, through of a multifaceted vision. The findings present in the paper are based on a two-year case study in a metallurgic equipment manufacturing enterprise in China. Based on the analysis of HEMP management problems and the contributions on systemic approach application in project management, the paper enriches existing theory by: (1) interpreting the HEMP management system with the top-down disassembly method; (2) developing the collaborative project management approach with a systems view highlighting the project characteristics management and inter-departmental collaboration; (3) making suggestions for systemic approach application in project management. For practitioners and researchers, the findings are particularly meaningful for manufacturing project management and systemic approach application.     

Optimal policy with a total order quantity commitment contract in the presence of a spot market

In this paper,the optimal policy is considered when the buyer faces two supply sources:one is the contract supplier from which the buyer orders over a specific contract period(say,a year) at a pre-agreed price,and the other is the spot market.However,when ordering from the contract supplier,the buyer must fulfill a pre-determined total order quantity,or the so-called definite total order quantity commitment,over the whole contract period.In other words,the commitment secures the buyer a fixed price but obliges him/her a total order quantity over the contract period.Although the spot market gives the buyer more flexibility in terms of order quantities,its prices are volatile.Such a combination of contract and spot procurements is often observed in practice.Within the contract period,there are multiple sub-periods,during each of which the buyer reviews the inventory,issues an individual order,and uses the on-hand inventory to meet the random demand.Thus,in each(ordering) period,the buyer will weigh between the current known spot price(by procuring from the spot market) and a lower future price(by waiting while consuming the remaining commitment).An optimal dual ordering policy is characterized for each period,depending on the on-hand inventory level,the spot price,and the remaining commitment quantity.The optimal policy in each period is also shown to be independent of the contract price.Through a numerical study,the inventory cost is demonstrated to be(1) insensitive to the contract price when the total commitment quantity is lower than the total expected demand over the contract period and(2) non-increasing in the variability of spot prices.     

On-chip natural assembly of silicon photonic bandgap crystals.

Photonic bandgap crystals can reflect light for any direction of propagation in specific wavelength ranges. This property, which can be used to confine, manipulate and guide photons, should allow the creation of all-optical integrated circuits. To achieve this goal, conventional semiconductor nanofabrication techniques have been adapted to make photonic crystals. A potentially simpler and cheaper approach for creating three-dimensional periodic structures is the natural assembly of colloidal microspheres. However, this approach yields irregular, polycrystalline photonic crystals that are difficult to incorporate into a device. More importantly, it leads to many structural defects that can destroy the photonic bandgap. Here we show that by assembling a thin layer of colloidal spheres on a silicon substrate, we can obtain planar, single-crystalline silicon photonic crystals that have defect densities sufficiently low that the bandgap survives. As expected from theory, we observe unity reflectance in two crystalline directions of our photonic crystals around a wavelength of 1.3 micrometres. We also show that additional fabrication steps, intentional doping and patterning, can be performed, so demonstrating the potential for specific device applications.     

Immune recognition. A new receptor for beta-glucans.

The carbohydrate polymers known as beta-1,3-d-glucans exert potent effects on the immune system - stimulating antitumour and antimicrobial activity, for example - by binding to receptors on macrophages and other white blood cells and activating them. Although beta-glucans are known to bind to receptors, such as complement receptor 3 (ref. 1), there is evidence that another beta-glucan receptor is present on macrophages. Here we identify this unknown receptor as dectin-1 (ref. 2), a finding that provides new insights into the innate immune recognition of beta-glucans.     

Water capture by a desert beetle.

Some beetles in the Namib Desert collect drinking water from fog-laden wind on their backs. We show here that these large droplets form by virtue of the insect's bumpy surface, which consists of alternating hydrophobic, wax-coated and hydrophilic, non-waxy regions. The design of this fog-collecting structure can be reproduced cheaply on a commercial scale and may find application in water-trapping tent and building coverings, for example, or in water condensers and engines.