bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigations of structure and dynamics of water solvation of the type I antifreeze protein
Authors: Cui Jun , Battle Keith , Wierzbicki Andrzej , Madura Jeffry D.
Published: August 2008

We use molecular dynamics simulations to study the water structure and dynamics around the winter flounder antifreeze protein (AFP) and its two mutant forms in which the four key threonine residues of the winter flounder AFP are mutated to alanines and serines, respectively. The TIP4P‐Ew water model is used to better describe the water interactions and water structure; all simulations are performed at 245.5 K, a temperature near the freezing point of the TIP4P‐Ew water model. Analysis of structural and dynamic properties of the water around the threonines in the winter flounder AFP reveals that the water structure is ordered around the threonine residues, especially in the second‐solvation shell. Alanine and serine mutations instead promote water hydration in the first‐solvation shell. Also our calculations show that in the close vicinity of the threonine residues of the wild‐type AFP, the mobility of water molecules is substantially decreased. A smaller effect is observed for the weakly active alanine‐substituted mutant, and no effect is observed for the inactive serine‐substituted mutant. The results of this study suggest that water ordering and immobilization play important roles in the recognition and adsorption of the antifreeze protein to ice. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Equivalent non‐linear single‐degree‐of‐freedom system of spatial asymmetric multi‐storey buildings in pushover procedure: theory and applications
Authors: Makarios Triantafyllos K.
Published: August 2008

In the present paper, the issue of the approximate definition of a new equivalent non‐linear single‐degree‐of‐freedom (NLSDF) system on spatial asymmetric reinforced concrete (r/c) tall multi‐storey buildings is presented. In order to achieve this goal, three different types of r/c systems are examined: the first type refers to multi‐storey planar r/c frames; the second type refers to asymmetric single‐storey r/c building; and the third type refers to asymmetric multi‐storey r/c buildings. The definition of the NLSDF system is mathematically derived, considering suitable dynamic loadings on the masses of each r/c system using simplified assumptions. The NLSDF system is very useful in the seismic design of the r/c systems, since it is widely used in all forms of various pushover analyses that have been published in the past. The use of the equivalent NLSDF system in combination with the inelastic design spectra can give an acceptable evaluation of the maximum required seismic floor displacement for a known design earthquake. The present paper concludes the total theory of definition of the optimum equivalent NLSDF system for the above three types of buildings that possess the required normality by the contemporary seismic codes in elevation. In order to illustrate the theory, three numerical examples are presented, respectively. The final numerical required displacement results by the use of the equivalent NLSDF system are verified and checked by non‐linear response history analyses. Copyright © 2008 John Wiley & Sons, Ltd.
Shaking table model tests on a complex high‐rise building with two towers of different height connected by trusses
Authors: Lu Xilin , Chen Linzhi , Zhou Ying , Huang Zhihua
Published: August 2008

The past decades have witnessed a flourish of novel high‐rise structures throughout the world under the requirement of a ceaselessly progressing architectural aesthetics, resulting in a complex plan and elevation of a building. Shanghai International Design Center is such a high‐rise building with two towers of different heights connected by trusses, and the structural system is composed of steel frame, reinforced concrete (RC) core wall and shear walls. The great irregularity in plan and elevation, according to Chinese code, necessitates a detailed study, which usually includes refined structural analysis, scaled structural model test and large size member or joint test. As recommended by the peer review committee, the shaking table tests of the 1:15‐scale structural model were performed. Based on the analysis and shaking table model testing, it was found that the stiffness of the connecting trusses is capable of coordinating the two towers to resist lateral forces jointly even under strong earthquakes. As a result of stiffening action brought by the connecting trusses, whipping‐lash effect in longitudinal direction develops sharply on top storeys. Structural responses at storeys around the connecting trusses vary remarkably due to sudden change in lateral stiffness. Through comparison between tests and numerical analysis, weak positions of the structure are identified, and some corresponding measures for improving the design of this structure are also put forward. Copyright © 2008 John Wiley & Sons, Ltd.
Photogrammetry of fetal breathing movements during the third trimester of pregnancy: observations in normal and abnormal pregnancies
Authors: Florido J. , Padilla M. C. , Soto V. , Camacho A. , Moscoso G. , Navarrete L.
Published: August 2008

Objective

To evaluate parameters of fetal breathing movements—displacement of the fetal abdominal wall during inspiration and expiration, time of inspiration and expiration and speed of inspiration and expiration—between 30 and 36 weeks' gestation in normal pregnancies, and in those complicated by gestational diabetes or maternal hypertension.

Methods

Three categories of pregnancy were investigated: 49 were normal, 16 had pregnancy‐induced diabetes and 10 were hypertensive. According to their gestational age, the patients were divided into two groups: Group A between 30 and 32 weeks' gestation and Group B between 33 and 36 weeks. Using photogrammetry and a computer‐operated algorithm, six parameters of fetal breathing movements were investigated.

Results

There were significant differences in the various fetal parameters measured among the three categories of pregnant women. Up until 32 weeks of gestation, the displacements during inspiration and expiration were larger, the speeds of inspiration and expiration were higher, and the times for inspiration and expiration were shorter in the diabetic and hypertensive groups than in the normal group. In the later period, between 33 and 36 weeks, fetuses of pregnancy‐induced diabetic patients showed the lowest inspiration and expiration times and the highest speeds of inspiration and expiration.

Conclusions

Photogrammetry in conjunction with a computer‐operated algorithm can be used to assess fetal breathing movements. There are significant differences in fetal breathing movements between normal pregnancies and those that are complicated by gestational diabetes or hypertension. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Surgical Margin Status and Prognosis of Gastrointestinal Stromal Tumor
Authors: Gouveia António M. , Pimenta Amadeu P. , Capelinha Ana F. , de la Cruz Dionísio , Silva Paula , Lopes José M.
Published: August 2008

Background

Surgery is the best treatment for primary GIST and may be curative, but resection extension/completeness impact on the prognosis remains controversial. The authors aim was to evaluate the clinicopathological (CP) parameters and surgical margins status influence on GIST patients’ outcome.

Materials and methods

The study evaluated 113 consecutive patients with sporadic GIST; the influence of CP parameters on recurrence‐free survival (RFS) and disease‐specific survival (DSS) was determined by univariate analysis (UA) and multivariate analysis (MA).

Results

Of 104 cases, macroscopically complete resection was achieved in 96: R0 surgical margin status in 78 and R1 in 18. Recurrence rates (12.5%) were significantly lower in R0 (9.0%) than in R1 (27.8%). Tumor >10 cm, mitotic count >5/50 high power field (HPF), and high‐risk GIST predicted poor RFS and DSS (UA). Disease‐specific survival was significantly shorter after macroscopic incomplete (R2) resection, for mixed cellular morphology, and in tumors with necrosis (UA). High‐risk GIST (p = 0.016) and R2 resection (p = 0.013) predicted poor DSS of patients (MA).

Conclusions

High risk and positive macroscopic surgical margin status are parameters associated with poor disease‐specific survival in GIST patients.
Ipsilateral femoral neck and shaft fractures: a retrospective analysis of two treatment methods
Authors: Singh Roop , Rohilla Rajesh , Magu Narender Kumar , Siwach Ramchander , Kadian Virender , Sangwan Sukhbir Singh
Published: August 2008

Background

No consensus exists regarding the optimal treatment of ipsilateral femoral neck and shaft fractures. The three major issues related to these fractures are the optimal timing of surgery, which fracture to stabilize first, and the optimal implant to use. In an effort to find answers to these three key issues, we report our experience of managing 27 patients with ipsilateral femoral neck and shaft fractures by using two different treatment methods, i.e., reconstruction-type intramedullary nailing and various plate combinations.

Materials and methods

We divided patients into two groups. Group I included 15 patients (13 males and 2 females) who were operated with cancellous lag screws or dynamic hip screws (DHS) for fractured neck and compression plate fixation for fractured shaft of the femur. Group II included 12 patients (11 males and 1 female) who were operated with reconstruction-type intramedullary nailing.

Results

Mean age was 33.2 and 37.9 years in group I and II, respectively. Mean delay in surgery was 5.9 and 5.4 days in group I and II, respectively. Average union time for femoral neck fracture in groups I and II were 15.2 and 17.1 weeks, respectively; and for shaft fracture these times were 20.3 and 22.8 weeks, respectively. There were 13 (86.6%) good, 1 (6.7%) fair and 1 (6.7%) poor functional results in group I. There were 10 (83.3%) good, 1 (8.3%) fair and 1 (8.3%) poor functional results in group II.

Conclusions

Both of the treatment methods used in the present study achieved satisfactory functional outcome in these complex fractures. Fixation with plate for shaft and screws or DHS for hip is easy from a technical point of view. Choice of the treatment method should be dictated primarily by the type of femoral neck fracture and the surgeon’s familiarity with the treatment method chosen. The femoral neck fracture should preferably be stabilized first, and a delay of 5–6 days does not affect the ultimate functional outcome.
Preparation and Characterization of Stimuli-Responsive Magnetic Nanoparticles
Authors: Wang ShiXing , Zhou Yang , Guan Wen , Ding Bingjun
Published: August 2008

In this work, the main attention was focused on the synthesis of stimuli-responsive magnetic nanoparticles (SR-MNPs) and the influence of glutathione concentration on its cleavage efficiency. Magnetic nanoparticles (MNPs) were first modified with activated pyridyldithio. Then, MNPs modified with activated pyridyldithio (MNPs-PDT) were conjugated with 2, 4-diamino-6-mercaptopyrimidine (DMP) to form SR-MNPs via stimuli-responsive disulfide linkage. Fourier transform infrared spectra (FTIR), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) were used to characterize MNPs-PDT. The disulfide linkage can be cleaved by reduced glutathione (GHS). The concentration of glutathione plays an important role in controlling the cleaved efficiency. The optimum concentration of GHS to release DMP is in the millimolar range. These results had provided an important insight into the design of new MNPs for biomedicine applications, such as drug delivery and bio-separation.
Analyses of velocity, acceleration, statics, and workspace of a 2(3-SPR) serial-parallel manipulator
Authors: Lu Yi , Hu Bo , Sun Tao
Published: August 2008

The kinematics, statics, and workspace of a 2(3-SPR) serial-parallel manipulator (S-PM) are studied systematically in this paper. First, a 2(3-SPR) S-PM including an upper 3-SPR parallel manipulator (PM) and a lower 3-SPR PM is constructed, and the inverse/forward displacements, velocity, acceleration, and statics of the lower and upper 3-SPR PMs are studied, respectively. Second, the kinematics and statics of the lower and upper 3-SPR PMs are combined and the displacement, velocity, acceleration, and statics of a 2(3-SPR) S-PM are analyzed systematically. Third, a workspace of the 2(3-SPR) S-PM is constructed and analyzed. Finally, the analytic solved results are given and verified by the simulation mechanism.
Partners in marriage and business? Guilds and the family economy in urban food markets in the Dutch Republic
Authors: VAN DEN HEUVEL DANIELLE
Published: August 2008

This article examines spousal cooperation in the early modern Dutch food markets. It shows that although husband and wife business partnerships were very common in market-based retailing, great differences existed in the way spouses worked together. Most urban retail trades were guild-organized and the guilds therefore had a significant influence on the family economy. Guild policy was, however, very flexible and responded to local economic circumstances. It appears that the size and the organization of the markets were crucial in shaping the roles of the men and women who held stalls. Processes of commercialization generally benefited independent female entrepreneurship over the more traditional husband and wife partnerships.
Societal change and individual past in connection with crime: demographic perspectives on young people arrested in northern Sweden in the nineteenth century
Authors: VIKSTRÖM LOTTA
Published: August 2008

Little is known about the lives of criminal offenders prior to their incarceration in past time. Knowing the background of offenders, however, may explain why they broke the law. This article explores young offenders in the Sundsvall region of Sweden, 400 kilometres north of Stockholm, an area with a booming sawmill-based economy in nineteenth-century Sweden. First, using prison registers, large-scale structural concepts are employed to explain the increasing number of incarcerations of young people reported during the period 1840–1880. Second, to uncover the offenders' demographic backgrounds and their socio-economic circumstances when arrested, they are identified in Swedish parish registers digitized by the Demographic Data Base (DDB) at Umeå University. These sources permit the application of retrospective life-course perspectives that are increasingly applied in modern criminology. These perspectives show that offenders were not primarily migrants or of poor origin, but that they frequently came from the region. Thus their parents were often also present in the community. In providing informal social control these characteristics – being local and having at least one parent nearby – are thought to lead to lower levels of criminality and imprisonment, but they were of little effect in preventing crime or incarceration. This study thus challenges the view of the criminal in past time as a lone individual arrested in an unfamiliar settings. Among the few female offenders observed, however, these factors were more typical; although gender accounts for low levels of criminality, their isolation and poverty did lead some women to theft.
Millian Superiorities and the Repugnant Conclusion
Authors: JENSEN KARSTEN KLINT
Published: August 2008

James Griffin has considered a form of superiority in value that is weaker than lexical priority as a possible remedy to the Repugnant Conclusion. In this article, I demonstrate that, in a context where value is additive, this weaker form collapses into the stronger form of superiority. And in a context where value is non-additive, weak superiority does not amount to a radical value difference at all. These results are applied on one of Larry Temkin's cases against transitivity. I demonstrate that Temkin appeals to two conflicting notions of aggregation. I then spell out the consequences of these results for different interpretations of Griffin's suggestion regarding population ethics. None of them comes out very successful, but perhaps they nevertheless retain some interest.
Nozick, Ramsey, and Symbolic Utility
Authors: COOPER WESLEY
Published: August 2008

I explore a connection between Robert Nozick's account of decision value/symbolic utility inThe Nature of Rationality1and F. P. Ramsey's discussion of ethically neutral propositions in his 1926 essay ‘Truth and Probability’,2a discussion that Brian Skyrms inChoice and Chance3credits with disclosing deeper foundations for expected utility than the celebratedTheory of Games and Economic Behavior4of von Neumann and Morgenstern. Ramsey's recognition of ethically non-neutral propositions is essential to his foundational work, and the similarity of these propositions to symbolic utility helps make the case that the latter belongs to the apparatus that constructs expected utility, rather than being reducible to it or being part of a proposal that can be cheerfully ignored. I conclude that decision value replaces expected utility as the central idea in (normative) decision theory. Expected utility becomes an approximation that is good enough when symbolic utility is not at stake.
Context, Character and Consequentialist Friendships
Authors: UPTON CANDACE L.
Published: August 2008

One prevailing objection to consequentialism holds that the consequentialist cannot promote both agent-neutral value and her own personal friendships: the consequentialist cannot be a genuine friend. Several versions of this objection have been advanced, but an even more sophisticated version of the charge is available. However, even this more sophisticated version fails, as it assumes a traditional, context-insensitive, account of character traits. In this article, I develop and defend a novel account of character traits that is context-sensitive and also supports a novel account of what friendship consists in. Application of the more plausible, contextual, account of character traits resolves the debate in favor of the friendly consequentialist.
A Consequentialist Distinction between What We Ought to Do and Ought to Try
Authors: PERSSON INGMAR
Published: August 2008

G. E. Moore raised the question of whether consequentialists ought to maximize actual rather than expected value, and came down in favour of the former alternative. But rather recently Frank Jackson has presented an example which has been widely thought to clinch the case in favour of the alternative view. This article argues for a sort of compromise between these rival views, namely that while we ought to do what maximizes actual value, we ought to try to do what maximizes expected value. It is claimed that consequentialists could consistently adopt this view, though in Jackson's case they are certain that, if they try to maximize expected value, they shall most likely not maximize actual value.
‘‘IF IT WERE GOD WHO SENT THEM . . .’’: ARISTOTLE AND AL-FĀRĀBĪ ON PROPHETIC VISION
Authors: STREETMAN W. CRAIG
Published: August 2008

Al-Fārābī’s title of ‘‘Second Teacher’’ after Aristotle is well-warranted. Al-Fārābī’s work serves to illuminate the writings of the ‘‘First Teacher’’ in interesting and overlooked ways that go beyond the parameters of Aristotelian logic. Credence is lent to this assessment through the analysis of a specific topic, namely, authentic prophetic vision. At first glance, this seems like a strange assertion to make given Aristotle’s apparent skepticism and indifference regarding the topic of prophecy. However, as this paper will show, there is a latent theory of prophetic vision in the extant texts of Aristotle that al-Fārābī recognizes and completes in a way that is, in large part, faithful to and consistent with the corpus of Aristotle as we read it today. In the end, al-Fārābī provides insight into how a properly Aristotelian theory of authentic prophetic vision could be realized.
Oscillations of the equatorward boundary of the ion auroral oval – radar observations
Authors: Jayachandran P. T. , Sato N. , Ebihara Y. , Yukimatu A. S. , Kadokura A. , MacDougall J. W. , Donovan E. F. , Liou K.
Published: August 2008

Three SuperDARN radars in the afternoon‐midnight sector of the auroral oval detected a boundary oscillation, originating near ∼1800 MLT sector. Analysis of the phase of the oscillations measured in three meridians indicates that the disturbance has a longitudinally (azimuthally) isolated source and away from which it propagates. The eastward and westward phase speeds are 2.6 and 3.6 km/s respectively and the period is roughly 28 minutes. An examination of the geo‐synchronous magnetic field inclination also revealed oscillations similar to the oscillations of the boundary. Solar wind and IMF conditions were steady during the period except for variations of the IMF By component. The IMF By component showed variations similar to the oscillations in the boundary and the geo‐synchronous magnetic field inclination. During reduced and negative IMF By, the boundary was moving equatorward, while during increased or positive IMF By it was moving poleward. The variations in the magnetic field inclination measured at geosynchronous orbit by the GOES satellites were consistent with these boundary motions: decreases (more stretched) and increases (more dipolar) in the inclination corresponded to equatorward and poleward moving boundaries, respectively. Polar cap convection also showed changes in the direction of the convection in response to the change in the IMF By component. Observed oscillation of the boundary can be explained by stretching of the tail field lines due to asymmetric merging associated with changes in the By component of the interplanetary magnetic field.
Pacific freshwater, river water and sea ice meltwater across Arctic Ocean basins: Results from the 2005 Beringia Expedition
Authors: Jones E. Peter , Anderson Leif G. , Jutterström Sara , Mintrop Ludger , Swift James H.
Published: August 2008

Pacific water, sea ice meltwater, and river water are the primary sources of freshwater in the Arctic Ocean. We have determined their relative fractions on a transect across the Arctic Ocean Section 2005 Expedition onboard IB Oden, which took place from 21 August to 23 September 2005. The transect began north of Alaska, continued through the central Canada Basin to the Alpha Ridge and into the Makarov Basin, and ended in Amundsen Basin. Pacific freshwater and river water were the major sources of freshwater throughout the central Canada Basin and into Makarov Basin, with river water fractions sometimes considerably higher than Pacific water in the top ∼50 m. Pacific freshwater extended to depths of about 200 m. Pacific water found over the Alpha Ridge and in the Amundsen Basin is suggested to have been transported there in the Transpolar Drift. The inventories of Pacific freshwater and river water were roughly constant along the section through most of the Canada and Makarov basins. River water fractions were greater than those of Pacific freshwater in the Amundsen Basin. Sea ice meltwater fractions were negative (reflecting net ice formation) or near zero throughout most of the section. A comparison of freshwater inventories with those at stations occupied during expeditions in 1991, 1994, and 1996 indicated an increase in river water inventories in the Makarov and Amundsen basins on the Eurasian side of the Arctic Ocean.
Optimization and sensitivity of a global biogeochemistry ocean model using combined in situ DIC, alkalinity, and phosphate data
Authors: Kwon Eun Young , Primeau François
Published: August 2008

We present a systematic parameter optimization and sensitivity analysis of a three‐dimensional global ocean biogeochemistry model. We use the global data sets of dissolved inorganic carbon (DIC), alkalinity, and phosphate to constrain the parameters of a biogeochemistry model which include the stoichiometric ratios rC:P and rN:P, the fraction σ of organic material production allocated to dissolved organic matter (DOM), the lifetime 1/κ of DOM, the exponent α in the power law for the depth profile of the remineralization of particulate organic carbon (POC), the rain ratio R of CaCO3, and the e‐folding length scale d for the depth profile of CaCO3 dissolution. The data‐constrained parameter values are rC:P = 137 ± 11, σ = 0.74 ± 0.04, 1/κ = 1.7 ± 0.5 years, α = −0.97 ± 0.07, R = 0.081 ± 0.008, and d = 2100 ± 300 m. The postoptimization carbon export from POC is 15 ± 1 Gt/a and from CaCO3 is 1.2 ± 0.1 Gt/a of which 67 ± 4% dissolves above 2000 m. The ± ranges indicate an average 1% decrease in the fraction of the spatial variance in the observed tracer data captured by the model. The sensitivity of the model to its parameters is presented in terms of sensitivity patterns defined as the derivative of the model's equilibrium tracer distribution with respect to the parameters (S patterns). The soft‐tissue, carbonate, and gas exchange pump mechanisms responsible for the sensitivities are presented. The pump decomposition of the S patterns illustrates quantitatively how changes in organic and inorganic carbon fluxes are coupled with the large‐scale ocean circulation and how the gas exchange pump couples to the global ventilation patterns through changes in surface chemistry.
Mechanisms of faulting in and around Caloris basin, Mercury
Authors: Kennedy Patrick J. , Freed Andrew M. , Solomon Sean C.
Published: August 2008

The distribution of faulting in and around the Caloris basin on Mercury provides constraints on the planet's early lithosphere and tectonic history. By means of a series of finite element models we test a range of ideas regarding lithospheric structure, surface loading, and shallow flow proposed to account for early contractional features and younger extensional features on the basin floor as well as contractional tectonic features exterior to the basin. Early‐stage thrust faults within the basin are well matched by the stress field accompanying flexural subsidence in response to partial infilling of a broad basin floor, while younger normal faulting can be the result of flexural uplift in response to later‐stage emplacement of an exterior annulus of smooth plains deposits. A proposed scenario in which later‐stage inward flow of the lower crust induces uplift of the basin floor can, under some conditions, yield extension in the basin, but not in a manner consistent with the observed distribution of normal faults. Thrust faulting on the exterior smooth plains can be the result of local subsidence accompanying the emplacement of these units but may also have been influenced by global contraction. Our results lead to the prediction that the gravity anomaly associated with the Caloris basin and surroundings should consist of a central positive anomaly (mascon) and an annular gravity high separated by a ring of lower gravity. Gravity and topography measurements to be made by the MESSENGER mission will provide a test of this prediction and more generally of the models developed here.
Response of deep‐sea CaCO3 sedimentation to Atlantic meridional overturning circulation shutdown
Authors: Chikamoto Megumi O. , Matsumoto Katsumi , Ridgwell Andy
Published: August 2008

Changes in the distribution of the preservation and burial of calcium carbonate (CaCO3) in deep ocean sediments and associated atmospheric pCO2 response to the shutdown of the Atlantic meridional overturning circulation (MOC) are examined using an Earth system model. We find that shutdown of the Atlantic MOC forced by the freshwater inflow significantly decreases the CaCO3 content in North Atlantic sediments. This is a consequence of a decrease in bottom‐water carbonate ion concentrations and reduction in sea‐surface CaCO3 production. The main sedimentary impacts of these two effects are separated in time, however, with reduced CaCO3 production dominating the decrease in CaCO3 burial during the first 1000 years after the forcing is applied. In the absence of significant overturning circulation in the Atlantic, atmospheric pCO2 increases by 11 ppm, largely due to a decrease in POC export and a weakening biological pump. The change in pCO2 induced by reorganization of CaCO3 burial in deep‐sea sediments is small, only 1 ppm, because increased preservation of CaCO3 in the Pacific largely efficiently buffers decreased preservation in the Atlantic, leaving the global burial and ocean alkalinity minimally changed at equilibrium.
Endosomal lipid accumulation in NPC1 leads to inhibition of PKC, hypophosphorylation of vimentin and Rab9 entrapment
Authors: Walter Marc , Chen Fannie W. , Tamari Farshad , Wang Rong , Ioannou Yiannis A.
Published: August 2008

Background information. Within the group of lysosomal storage diseases, NPC1 [NPC (Niemann‐Pick type C) 1] disease is a lipidosis characterized by excessive accumulation of free cholesterol as well as gangliosides, glycosphingolipids and fatty acids in the late E/L (endosomal/lysosomal) system (Chen et al., 2005) due to a defect in late endosome lipid egress. We have previously demonstrated that expression of the small GTPase Rab9 in NPC1 cells can rescue the lipid transport block phenotype (Walter et al., 2003), albeit by an undefined mechanism.

Results. To investigate further the mechanism by which Rab9 facilitates lipid movement from late endosomes we sought to identify novel Rab9 binding/interacting proteins. In the present study, we report that Rab9 interacts with the intermediate filament phosphoprotein vimentin and this interaction is altered by lipid accumulation in late endosomes, which results in inhibition of PKC (protein kinase C) and hypophosphorylation of vimentin, leading to late endosome dysfunction. Intermediate filament hypophosphorylation, aggregation and entrapment of Rab9 ultimately leads to transport defects and inhibition of lipid egress from late endosomes.

Conclusions. These results reveal a previously unappreciated interaction between Rab proteins and intermediate filaments in regulating intracellular lipid transport.
A novel way to purify recombinant baculoviruses by using bacmid
Authors: Su Wu-Jie , Shen Wei-De , Li Bing , Wu Yan , Gao Guang , Wang Wen-Bing
Published: August 2008

In the present study, we studied the feasibility of deleting essential genes in insect cells by using bacmid and purifying recombinant bacmid in Escherichia coli DH10B cells. To disrupt the orf4 (open reading frame 4) gene of BmNPV [Bm (Bombyx mori) nuclear polyhedrosis virus], a transfer vector was constructed and co-transfected with BmNPV bacmid into Bm cells. Three passages of viruses were carried out in Bm cells, followed by one round of purification. Subsequently, bacmid DNA was extracted and transformed into competent DH10B cells. A colony harbouring only orf4-disrupted bacmid DNA was identified by PCR. A mixture of recombinant (white colonies) and non-recombinant (blue colonies) bacmids were also transformed into DH10B cells. PCR with M13 primers showed that the recombinant and non-recombinant bacmids were separated after transformation. The result confirmed that purification of recombinant viruses could be carried out simply by transformation and indicated that this method could be used to delete essential genes. Orf4-disrupted bacmid DNA was extracted and transfected into Bm cells. Viable viruses were produced, showing that orf4 was not an essential gene.
Direct measurement of hot-spot temperature in flip-chip solder joints under current stressing using infrared microscopy
Authors: Hsiao Hsiang-Yao , Liang S. W. , Ku Min-Feng , Chen Chih , Yao Da-Jeng
Published: August 2008

Several simulation studies reported that a hot spot exists in flip-chip solder bumps under accelerated electromigration. Yet, there are no experimental data to verify it. In this paper, the temperature distribution during electromigration in flip-chip SnAg3.5 solder bumps is directly inspected using infrared microscopy. Two clear hot spots are observed in the bump. One is located at the region with peak current density and the other one is at the bump edge under the current-feeding metallization on the chip side. Under a current stress of 1.06×104A∕cm2, the temperature in the two hot spots are 161.7 and 167.8°C, respectively, which surpass the average bump temperature of 150.5°C. In addition, the effect of under-bump-metallization (UBM) thickness on the hot spots is also examined. It indicates that the hot-spot temperature in the solder bump increases for the solder joints with a thinner UBM. Electromigration test indicates that these hot spots have significant influence on the initial failure location.
Full configuration interaction calculation of BeH adiabatic states
Authors: Pitarch-Ruiz J. , Sánchez-Marin J. , Velasco A. M. , Martin I.
Published: August 2008

An all-electron full configuration interaction (FCI) calculation of the adiabatic potential energy curves of some of the lower states of BeH molecule is presented. A moderately large ANO basis set of atomic natural orbitals (ANO) augmented with Rydberg functions has been used in order to describe the valence and Rydberg states and their interactions. The Rydberg set of ANOs has been placed on the Be at all bond distances. So, the basis set can be described as 4s3p2d1f∕3s2p1d(Be∕H)+4s4p2d(Be). The dipole moments of several states and transition dipole strengths from the ground state are also reported as a function of the RBe–H distance. The position and the number of states involved in several avoided crossings present in this system have been discussed. Spectroscopic parameters have been calculated from a number of the vibrational states that result from the adiabatic curves except for some states in which this would be completely nonsense, as it is the case for the very distorted curves of the 3s and 3pΣ+2 states or the double-well potential of the 4pΠ2 state. The so-called “D complex” at 54050cm−1 (185.0nm) is resolved into the three 3d substates (Σ+2,Π2,Δ2). A diexcited valence state is calculated as the lowest state of Σ−2 symmetry and its spectroscopic parameters are reported, as well as those of the 2Δ2 (4d) state The adiabatic curve of the 4Σ+2 state shows a swallow well at large distances (around 4.1Å) as a result of an avoided crossing with the 3Σ+2 state. The probability that some vibrational levels of this well could be populated is discussed within an approached Landau–Zerner model and is found to be high. No evidence is found of the E(4sσ) Σ+2 state in the region of the “D complex”. Instead, the spectroscopic properties obtained from the (4sσ) 6Σ+2 adiabatic curve of the present work seem to agree with those of the experimental F(4pσ) Σ+2 state. The FCI calculations provide benchmark results for other correlation models for the open-shell BeH system and evidence both the limitations and capabilities of the basis set.
Rigidity effect on phase behavior of symmetric ABA triblock copolymers: A Monte Carlo simulation
Authors: Song Jianhui , Shi Tongfei , Li Yunqi , Chen Jizhong , An Lijia
Published: August 2008

The phase behavior of symmetric ABA triblock copolymers containing a semiflexible midblock is studied by lattice Monte Carlo simulation. As the midblock evolves from a fully flexible state to a semiflexible state in terms of increase in its persistence length, different phase behaviors are observed while cooling the system from an infinite high temperature to a temperature below TODT (order-disorder transition temperature). Within the midblock flexibility range we studied (lp∕Nc⩽0.105), a lamellar structure is formed at equilibrium state as the situation for fully flexible chains. The fraction of bridge chain is evaluated for the lamellar structures. We find that the increase in midblock rigidity indeed results in the increase in bridge chain fraction within the range from 44.9% to 51.8%. In order to elucidate phase behavior evolution observed in our simulation, a detailed conformation distribution analysis is also given. Our results bridge a gap of different phase behaviors between rod-coil block copolymer and coil-coil block copolymer and show a necessity to investigate rigidity influence on phase diagram.
Beyond electronegativity and local hardness: Higher-order equalization criteria for determination of a ground-state electron density
Authors: Ayers Paul W. , Parr Robert G.
Published: August 2008

Higher-order global softnesses, local softnesses, and softness kernels are defined along with their hardness inverses. The local hardness equalization principle recently derived by the authors is extended to arbitrary order. The resulting hierarchy of equalization principles indicates that the electronegativity/chemical potential, local hardness, and local hyperhardnesses all are constant when evaluated for the ground-state electron density. The new equalization principles can be used to test whether a trial electron density is an accurate approximation to the true ground-state density and to discover molecules with desired reactive properties, as encapsulated by their chemical reactivity indicators.
A molecular dynamics study of chirality transfer: The impact of a chiral solute on an achiral solvent
Authors: Wang Shihao , Cann N. M.
Published: August 2008

A solvation shell may adapt to the presence of a chiral solute by becoming chiral. The extent of this chirality transfer and its dependence on the solute and solvent characteristics are explored in this article. Molecular dynamics simulations of solvated chiral analytes form the basis of the analysis. The chirality induced in the solvent is assessed based on a series of related chirality indexes originally proposed by Osipov [M. A. Osipov et al., Mol. Phys. 84, 1193 (1995)]. Two solvents are considered: Ethanol and benzyl alcohol. Ethanol provides insight into chirality transfer when the solvent interacts with the solute primarily by a hydrogen bond. Several ethanol models have been considered starting with a nonpolarizable model, progressing to a fluctuating charge model, and finally, to a fully polarizable model. This progression provides some insights into the importance of solvent polarizability in the transfer of chirality. Benzyl alcohol, by virtue of the aromatic ring, increases the number of potential solvent-solute interactions. Thus, with these two solvents, the issue of compatibility between the solvent and solute is also considered. The solvation of three chiral solutes is examined: Styrene oxide, acenaphthenol, and n-(1-(4-bromophenyl)ethyl)pivalamide (PAMD). All three solutes have the possibility of hydrogen bonding with the solvent, the last two may also form ring-ring interactions, and the last also has multiple hydrogen bonding sites. For PAMD, the impact of conformational averaging is examined by comparing the chirality transfer about rigid and flexible solutes.
The development of a Krook model for nonlocal transport in laser produced plasmas. I. Basic theory
Authors: Manheimer Wallace , Colombant Denis , Goncharov Valeri
Published: August 2008

This paper examines the Krook model as a means of quantifying the problem of nonlocal transport of electron energy in laser produced plasmas. The result is an expression for the nonlocal electron energy flux q. The roles of both flux limitation and preheat are clearly delineated. Furthermore, it develops a test for the validity of this model. This is a physics based, “first principles” model that can be economically incorporated into a fluid simulation.
Effects of rapid thermal annealing on optical properties of p-doped and undoped InAs/InGaAs dots-in-a-well structures
Authors: Cao Q. , Yoon S. F. , Liu C. Y. , Tong C. Z.
Published: August 2008

Postgrowth rapid thermal annealing was used to investigate the intermixing and structural changes in p-doped and undoped InAs/In0.1Ga0.9As dots-in-a-well (DWELL) structures grown by molecular beam epitaxy. Interdiffusion of In and Ga atoms caused by thermal annealing was proven from photoluminescence (PL) measurements, where blueshifts of the energy peaks were observed. The results show that p-doped quantum dot (QD) structures are more resistant to intermixing with higher thermal energy onset, and the reason is explained as the suppressed Ga diffusion resulted from the Be dopant. Rapid quenching of the integrated PL intensity at high temperature was observed in both undoped and p-doped DWELL QDs. Good agreement was obtained by fitting the integrated PL profile using two nonradiative recombination mechanisms, resulting in two activation energies that correspond to loss of carriers to nonradiative centers.
Efficient p-i-n type organic solar cells incorporating 1,4,5,8-naphthalenetetracarboxylic dianhydride as transparent electron transport material
Authors: Falkenberg Christiane , Uhrich Christian , Olthof Selina , Maennig Bert , Riede Moritz K. , Leo Karl
Published: August 2008

The implementation of proper charge carrier transport materials in p-i-n type organic solar cells strongly influences the device performance. Our investigation focuses on the substitution of the standard layer sequence used at the side of electron transport, usually consisting of either C60/exciton blocking layer/metal or n-C60/metal by a layer sequence including a window layer. Here, we evaluate the transparent electron transport material 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA), which guarantees a loss free charge extraction from the active materials due to a good energy level alignment as well as exciton blocking due to its wide bandgap. It is demonstrated that upon the exchange of the electron transport layer n-C60 for n-NTCDA, the solar power conversion efficiency of a p-i-n device can be increased by 10%.
Image potentials of single-walled carbon nanotubes in the field emission condition
Authors: Wang Weiliang , Peng Jie , Chen Guihua , Deng Shaozhi , Xu Ningsheng , Li Zhibing
Published: August 2008

We calculated the image potentials of single-walled carbon nanotubes of various structures with a quantum chemistry method. The image potentials of the single-walled carbon nanotubes can be well fitted with the image potential of an ideal metal sphere of a size comparable to an atom. The image potentials are not sensitive to the applied fields and the structures of the tubes. When the image potentials are included, the emission current increases by one order.
Enhancing power conversion efficiencies and operational stability of organic light-emitting diodes by increasing carrier injection efficiencies at anode/organic and organic/organic heterojunction interfaces
Authors: Matsushima Toshinori , Murata Hideyuki
Published: August 2008

We fabricated long-lived multilayer organic light-emitting diodes (OLEDs), in which a 0.75 nm thick hole-injection layer of molybdenum oxide (MoO3) and a 5 nm thick mixed layer at an organic/organic heterojunction interface were embedded. The use of the MoO3 layer and of the mixed layer enhanced carrier injection at anode/organic and organic/organic heterojunction interfaces, resulting in a marked decrease in driving voltage and an increase in power conversion efficiency in the OLEDs. We observed about a factor of 9 improvement in the operational lifetime of the OLEDs by using the MoO3 layer and the mixed layer as well. We assume that the lifetime improvement originates from the suppression of a thermally induced electrochemical degradation process of organic emitting molecules due to the reduction in the probability of the generation of Joule heat.
Focusing mirror for x-ray free-electron lasers
Authors: Mimura Hidekazu , Morita Shinya , Kimura Takashi , Yamakawa Daisuke , Lin Weimin , Uehara Yoshihiro , Matsuyama Satoshi , Yumoto Hirokatsu , Ohashi Haruhiko , Tamasaku Kenji , Nishino Yoshinori , Yabashi Makina , Ishikawa Tetsuya , Ohmori Hitoshi , Yamauchi Kazuto
Published: August 2008

We present the design, fabrication, and evaluation of a large total-reflection mirror for focusing x-ray free-electron laser beams to nanometer dimensions. We used an elliptical focusing mirror made of silicon that was 400mm long and had a focal length of 550mm. Electrolytic in-process dressing grinding was used for initial-step figuring and elastic emission machining was employed for final figuring and surface smoothing. A figure accuracy with a peak-to-valley height of 2nm was achieved across the entire area. Characterization of the focused beam was performed at BL29XUL of SPring-8. The focused beam size was 75nm at 15keV, which is almost equal to the theoretical size.
A nuclear magnetic resonance study on rubrene-cobalt nanocomposites
Authors: Shiraishi Masashi , Kusai Haruka , Nouchi Ryo , Nozaki Takayuki , Shinjo Teruya , Suzuki Yoshishige , Yoshida Makoto , Takigawa Masashi
Published: August 2008

We implemented a nuclear magnetic resonance (NMR) study on rubrene (C42H28)−Co nanocomposites that exhibit an enhanced magnetoresistance (MR) ratio of 80%. The C59o NMR spin echo experiment enabled clarification of the hyperfine field of Co at the interface between the ferromagnet and the molecules, which has not been investigated for molecular spintronics. An enhanced hyperfine field of the Co was observed in the rubrene-Co nanocomposites, which may be related to the enhancement of the MR ratio. This study demonstrates the importance of microscopic investigation of the interface between molecules and ferromagnets that governs spin-dependent transport in molecular spin devices.
Solution-processed organic thin-film transistors with vertical nanophase separation
Authors: Ohe Takahiro , Kuribayashi Miki , Yasuda Ryoichi , Tsuboi Ami , Nomoto Kazumasa , Satori Kotaro , Itabashi Masao , Kasahara Jiro
Published: August 2008

We have found that spin coating a solution of 6,13-bis(triisopropyl-silylethynyl)-pentacene (TIPS-pentacene) blended with poly(α-methylstyrene) (PαMS) induces vertical nanophase separation, which results in a trilayer film: a TIPS-pentacene layer, a mixed layer of TIPS-pentacene/PαMS, and a TIPS-pentacene layer. Organic thin-film transistors (TFTs) made from this TIPS-pentacene/PαMS solution have remarkably improved uniformity and thermal stability without degradation of electrical characteristics compared to organic TFTs with a conventional TIPS-pentacene sole channel layer.
High-performance nanowire complementary metal-semiconductor inverters
Authors: Ma R. M. , Dai L. , Liu C. , Xu W. J. , Qin G. G.
Published: August 2008

We demonstrated the construction of complementary metal-semiconductor (CMES) inverters with single n- and p-type nanowires (NWs) on the same chip. A single p-type NW was assembled by the side of an n-type NW via the electric field assembly method. n- and p-channel metal-semiconductor field-effect transistors were fabricated with n- and p-type NWs, respectively. Based on this, high-performance NW CMES NOT logic gate (inverter) was built. The NW CMES inverters have low operating voltage (≤2 V), high voltage gain (≥7), and low static power dissipation (≤0.3 nW).
Separation modes in microcontacts identified by the rate dependence of the pull-off force
Authors: Chen L. , McGruer N. E. , Adams G. G. , Du Y.
Published: August 2008

We report the observation of two distinct modes of rate-dependent behavior during contact cycling tests. One is a higher pull-off force at low cycling rates and the other is a higher pull-off force at high cycling rates. Subsequent investigation of these contacts using scanning electron microscopy (SEM) demonstrates that these two rate-dependent modes can be related to brittle and ductile separation modes. The former behavior is indicative of brittle separation, whereas the latter accompanies ductile separation. Thus by monitoring the rate dependence of the pull-off force, the type of separation mode can be identified during cycling without interrupting the test to perform SEM.