nils-herrmann/clean_scirepeval huggingface dataset:
Research on Weldability of High Aluminum Dual Phase Steel WHT600DP for Spot Welding

The weldability for spot welding of 600 MPa high aluminum dual phase steel WHT600DP,which was newly developed by WISCO,was studied by microstructure observation,hardness test and tensile shearing strength test of the joint between WHT600DP and different materials,such as DC03 and WH260Y.The results show that the joints are free of defects,and the weld performances such as tensile shear strength can meet the requirements of automobile industry,which indicate the excellent weldability of WHT600DP steel.

Field of study: Materials science
Effects of Minor Ni Doping on Microstructural Variations
and Interfacial Reactions in Cu/Sn-3.0Ag-0.5Cu-xNi/Au/Ni Sandwich Structures

The effects of Ni doping on microstructural variations and interfacial reactions in Cu/Sn-3.0Ag-0.5Cu-xNi/Au/Ni sandwich structures were investigated. The sandwich structures, i.e., Cu/Sn-3.0Ag-0.5Cu/Au/Ni and Cu/Sn-3.0Ag-0.5Cu-0.1Ni/Au/Ni (wt.%), were reflowed and isothermally aged at 150°C for 500 h. The behavior of Ni and Cu migration in the solders before and after aging was investigated using field-emission electron probe microanalysis (FE-EPMA), and the microstructure evolution of the solders with Ni doping was investigated. It was observed that Ni migrated to the board Cu-side, while Cu tended to migrate toward the Ni/Au package side, and two different types of (Cu,Ni)6Sn5 intermetallic compounds (IMCs), one with 19.8 at.% to 23.4 at.% Ni and the other with 1.3 at.% to 6.4 at.% Ni content, were found. Regarding interfacial reactions, it was identified that the local Ni and Cu concentrations affected the formation of (Cu,Ni)6Sn5. Redistribution of Ni and Cu was correlated with the formation mechanism of interfacial (Cu,Ni)6Sn5.

Field of study: Materials science
The Supreme Court and the New Politics of Judicial Power

Most observers of American politics expected the results of the 1968 presidential election to have major implications for the future of American constitutional law. In the year prior to the election, Chief Justice Earl Warren had announced his retirement and President Lyndon Johnson's efforts to promote his friend and confidant, Associate Justice Abe Fortas, to the post had failed. The successful presidential candidate was thus assured the opportunity to appoint a chief justice. Moreover, the advanced age of several other justices virtually guaranteed the new President additional appointments. Staffing the judiciary became an important political issue as Richard Nixon mounted a vigorous "law and order" campaign, in which he sought to link rising crime rates to the criminal process decisions of the Warren Court and promised to stem the tide of judicial activism by appointing only "strict constructionists" to the Supreme Court. Nixon's victory in 1968 thus appeared to set the stage for a judicial "counterrevolution," a determined effort by the executive branch to set aside the liberal jurisprudence of the Warren Court through the use of the appointment power. This effort gathered momentum as the nomination of a new chief justice was quickly followed by the resignation of Justice Fortas and the deaths of Justices Hugo L. Black and John M. Harlan. Within his first three years in office, Nixon was

Field of study: Political science
Pharmacological actions of miltirone in the modulation of platelet function

Salvia miltiorrhiza Bunge contains various active constituents, some of which have been developed as commercially available medicine. Moreover, some other ingredients in Salvia miltiorrhiza play roles in anti-platelet activity. The aim of the present study was to investigate the effects and the underlying mechanism of miltirone, a lipophilic compound of Salvia miltiorrhiza Bunge. The ability of miltirone to modulate platelet function was investigated by a variety of in vitro and in vivo experiments. Platelet aggregation and dense granule secretion induced by various agonists were measured with platelet aggregometer. Clot retraction and spreading were imaged by digital camera and fluorescence microscope. Ferric chloride-induced carotid injury model and pulmonary thromboembolism model were used to check miltirone antithrombotic effect in vivo. To elucidate the mechanisms of anti-platelet activity of miltirone, flow cytometry and western blotting were performed. Miltirone (2, 4, 8 µM) was shown to suppress platelet aggregation, dense granule, and α granule secretion in a dose-dependent manner. Meanwhile, miltirone inhibited the clot retraction and spreading of washed platelets. It reduced the phosphorylation of PLCγ2, PKC, Akt, GSK3β and ERK1/2 in the downstream signal pathway of collagen receptor. It also reduced the phosphorylation of Src and FAK in the integrin αIIbβ3-mediated “outside-in” signaling, while it did not suppress the phosphorylation of β3. In addition, miltirone prolonged the occlusion time and reduced collagen/epinephrine-induced pulmonary thrombi. Miltirone suppresses platelet “inside-out” and “outside-in” signaling by affecting PLCγ2/PKC/ERK1/2, PI3K/Akt, and Src/FAK signaling. Therefore, miltirone might represent a potential anti-platelet candidate for the prevention of thrombotic disorders.

Field of study: Biology, Chemistry, Medicine
Two remarks on Heisenberg’s theory of isotropic turbulence

Equation (3) states that the spatial rate of change of the distribution function 2V(r, s) at the position r, in the direction of the unit vector s, is due to three effects which appear on the right side of the equation. They are, in order of their appearance, first, radiation lost through absorption, and scattering out of the direction s; secondly radiation which is scattered from all 4ir solid angle into the direction s. p(0) is the angular differential cross section for the specific process involved. Thirdly there is the source contribution <S. It is assumed in the above equation that a scatter is not accompanied by a change in wave length, n is the total narrow beam absorption coefficient. When the solution of (3) is through expansion processes, Eq. (2) becomes a useful integral formula for reducing the integral of (3) to its equivalent summation. For instance, consider the problem which permits the unit vector s to be replaced by the ordinate angle 6 (e.g., spherical symmetry and infinite plane source). In this case the distribution function may be expanded as

Field of study: Mathematics
CAALIGN: a program for pairwise and multiple protein-structure alignment.

Coordinate superposition of proteins provides a structural basis to protein similarity and therefore complements the technique of sequence alignment. Methods that carry out structure alignment are faced with the problem of the large number of trials necessary to determine the optimal alignment solution. This article presents a method of carrying out rapid (subsecond) protein-structure alignment between pairs of proteins based on a maximal C(alpha)-atom superposition. The algorithm can return alignments of 12 or more residues in length as multiple non-overlapping solutions of alignment between a pair of proteins which are independent of the fold connectivity and secondary-structure content. The algorithm is equally effective for all protein fold types and can align proteins containing no secondary-structure elements such as is the case when searching for common turn structures in proteins. It has high sensitivity and returns the set of true positive results before any false positives as judged by SCOP classification. It can find alignments between topologically different folds and returns information about sequence alignment based on structure alignment. Additionally, this algorithm has been extended to carry out multiple structure alignment to determine common structures within groups of proteins, including the nondegenerate set of proteins in the PDB. The algorithm has been implemented within the program CAALIGN and this article presents results from pairwise structure alignment, multiple structure alignment and the generation of common structure fragments found within the PDB using multiple structure alignment.

Field of study: Chemistry
Creating structure features by data mining the PDB to use as molecular-replacement models.

Mathematical data-mining techniques to generate a representative set of protein fragments are described. Protein fragments are used as search models within the macromolecular phasing method of molecular replacement to attempt to phase protein data without a homologous model correctly. Preliminary investigations using these fragments indicate that molecular replacement with AMoRe is not sensitive enough to phase myoglobin or insulin data sufficiently for successful refinement. The results suggest that more advanced molecular replacement techniques may be successful, though at present these are not computationally practical.

Field of study: Chemistry
Analysis of the smoothing performance of a rapid polarization rotation smoothing scheme.

In order to improve the irradiation uniformity on the target plane and reduce the parametric backscattering in indirect-drive inertial confinement fusion facilities, a rapid polarization rotation smoothing scheme is proposed. In this scheme, there is a central wavelength shift between adjacent beams in a laser quad. Two of these beams are transformed into left-rotating circularly polarized beams by using polarization control plates, and the other two are transformed into right-rotating circularly polarized beams. Moreover, conjugate spiral phase plates are adopted to transform the beams into conjugate Laguerre-Gaussian beams. As a result of the frequency beat among the beams with counter-rotating polarization and conjugate spiral phases, both the intensity distribution and polarization of the focal spot would rotate rapidly on the picosecond timescale. The physical model of the rapid polarization rotation smoothing scheme is built up, and the smoothing performance affected by the parameters of spiral phase plates, polarization control errors, wavelength shift, and wavefront distortions is analyzed in detail. The results indicate that the rapid polarization rotation smoothing scheme has a relatively wide tolerance to the polarization errors and the spiral phase plates, and can improve the smoothing performance effectively with the combination of the smoothing by spectral dispersion scheme.

Field of study: Physics
Climate and environment of a Pliocene warm world

The Pliocene Epoch, 5.33–2.58 million years ago (Ma), was a generally warmer and wetter interval with atmospheric CO2-concentrations at or slightly above modern levels. This paper provides an overview of Pliocene vegetation, sea surface temperatures and climate modelling outcomes. Most prominent changes in Pliocene biome distribution compared to today include a northwards shift of temperate and boreal vegetation zones in response to a warmer and wetter climate as well as an expansion of tropical savannas and forests at the expense of deserts. Faunal analysis techniques and modelling experiments using the Hadley Centre climate model identified significantly higher Pliocene sea surface temperatures at mid and high latitudes of the northern hemisphere with cooling or unchanged sea surface temperatures at low latitudes. Global mean annual surface temperatures (MAT) are estimated to have been 2 to 3 °C higher during the Piacenzian (3.6–2.58 Ma) than today with a reduced equator to pole gradient. The marine realm during the Pliocene was characterised by a reconfiguration of ocean gateways, particularly the narrowing of the Indonesian Seaway and closure of the Central American Isthmus, which produced essentially a modern pattern of ocean circulation. In the Southern Ocean a warm early Pliocene gave way to late Piacenzian cooling. Proxy data indicate a reduced east to west sea surface temperature gradient in the tropical Pacific during the Pliocene warmth. The Pliocene is one of the most intensively studied geological intervals of the pre-Quaternary. No other warm period in the geological past yields such a unique combination of near modern atmospheric CO2-concentrations, palaeogeography and palaeobiology. However, this paper also identifies data gaps and shortcomings in the reconstruction of Pliocene environments using proxy data and climate models on which future research should focus.

Field of study: Environmental science, Geography
γδ T cells in Behçet's disease (BD) and recurrent aphthous stomatitis (RAS)

The immunopathogenesis of BD is believed to be T cell‐mediated. The objective of this study was to characterize the activation stage and cytokine profile of peripheral blood lymphocytes (PBL), with particular emphasis on γδ T cells. Venous blood was collected from 20 patients with BD, and for comparison, from 11 patients with RAS and from 15 healthy controls. Both the expression of activation markers (CD25, CD29, CD40 ligand, CD69 and HLA‐DR) on freshly isolated PBL and T cell subsets, and the expression of intracellular cytokines (IL‐4, IL‐10, interferon‐gamma (IFN‐γ) and tumour necrosis factor‐alpha (TNF‐α)) on mitogen‐stimulated PBL and T cell subsets were analysed by double immunofluorescent staining and flow cytometry. Significantly decreased proportion of αβ T cells and increased proportion of γδ T cells, CD56+ cells and CD8+γδ T cells were found in BD patients compared with healthy controls. This was also seen to a lesser extent in patients with RAS. Furthermore, in BD a significantly increased proportion of the γδ T cell population expressed CD69 and high levels of CD29 and were induced to produce IFN‐γ and TNF‐α compared with healthy controls. In contrast, an increased percentage of γδ T cells from RAS patients was induced to produce IFN‐γ, but not TNF‐α. These results indicate that in BD, activated γδ T cells, capable of producing IFN‐γ and TNF‐α, are present in peripheral blood, suggesting that γδ T cells are dynamic and may be regulating immunopathogenic events.

Field of study: Biology, Medicine
Glutamate-induced cytotoxicity in PC12 pheochromocytoma cells: role of oxidation of phospholipids, glutathione and protein sulfhydryls revealed by bcl-2 transfection.

Incubation of mock-transfected PC12 rat pheochromocytoma cells (PC12) for 2 h with increasing concentrations of glutamate caused progressive loss of viability (e.g., 67% with 15 mM glutamate). In contrast, the viability of bcl-2-transfected cells (PC12/bcl-2) was unaffected by glutamate. Neither PC12 nor PC12/bcl-2 cells showed a significant incidence of apoptosis in response to glutamate. Conventional phospholipid analysis by high-performance TLC and phosphorous determination showed no significant changes in the phospholipid composition of either cell line incubated with </=15 mM glutamate. Phospholipid peroxidation was quantified in the cells using our newly developed method based on fluorescence-HPLC analysis of metabolically incorporated oxidation-sensitive and fluorescent fatty acid, cis-parinaric acid. Unlike previous studies that measured total phospholipid oxidation, this novel technology permitted quantitation of oxidative stress in different classes of labeled phospholipids (the amount of labeled phospholipids in the cells did not exceed 1% of total phospholipids). Significant peroxidation of phosphatidylcholine and phosphatidylethanolamine occurred in PC12 cells treated with >5 mM glutamate. The peroxyl radical initiator 2,2'-azobis(2,4-dimethylvaleronitrile) caused a pronounced loss of all major phospholipid classes in PC12 cells, but no loss of cell viability. No phospholipid peroxidation was detected in PC12/bcl-2 cells incubated with </=15 mM glutamate or with 2, 2'-azobis(2,4-dimethylvaleronitrile). These results directly demonstrate that peroxidation of membrane phospholipids is not responsible for the cytotoxicity of glutamate in PC12 cells. Total cellular thiol, protein thiol and GSH reserves were quantified by a previously described electron paramagnetic resonance spectrometric method. Total thiols were ca. 1.5-fold greater in PC12/bcl-2 than in PC12 cells. Glutamate (</=5 mM) caused a progressive and equally significant decrease in total thiols and GSH in both PC12 and PC12/bcl-2 cells. High glutamate concentrations caused oxidation of protein sulfhydryls in PC12 cells, but not in PC12/bcl-2 cells. The results suggest that the changes in cellular milieu caused by bcl-2 gene transfection protect PC12 cells from the toxic effects of glutamate in a manner consistent with prevention of protein sulfhydryl oxidation.

Field of study: Biology
Home range of the Columbian mammoths (Mammuthus columbi) and grazing herbivores from the Waco Mammoth National Monument, (Texas, USA) based on strontium isotope ratios from tooth enamel bioapatite

Waco Mammoth National Monument (WMNM) is a central Texas, Late Pleistocene fossil site dating to ~67 ka. At least 23 Columbian mammoths (Mammuthus columbi), along with the remains of 12 other vertebrate genera have been discovered at this locality. Mammoth teeth were micro-sampled at a high resolution with a computerized micromill, whereas bison and horse teeth were serially sampled with a handheld rotary tool. Serial samples from these individuals offer insights into the movement patterns (87Sr/86Sr) of WMNM herbivores. Regional vegetation and local sediments were also collected to construct an 87Sr/86Sr isoscape to track past movement of mammals, derived from Sr analyses of teeth enamel. 87Sr/86Sr in WMNM herbivores often reflects multiple grazing provenances, and sources. A series of mixing models are proposed to understand the contribution of different surface Sr sources to herbivore diets. These data indicate one mammoth spent some time at the Llano uplift area ~180 km to the SSW during the formation of molar enamel. The remaining individuals (three mammoths, a bison and a horse) lived in an area more proximal to the WMNM, ≤70 km SE of the site. 87Sr/86Sr from WMNM mammoths indicate individual fidelity to at least two geographic ranges, with at least one mammoth, potentially unrelated to the possible matriarchal herd, indicating complex population dynamics prior to mass mortality. This analysis shows that at least 25 mammals, including the horse and bison, congregated at the confluence of Brazos and Bosque rivers at ~67 ka ago, prior to their demise. A resource shortage related to drought is consistent with this pattern.

Field of study: Environmental science, Geography
Substance abuse in the United States: Findings from recent epidemiologic studies

Recent research on the epidemiology of substance use disorders (SUDs) has provided important insights into these conditions and their impact on public health. In the United States, annual surveys of drug use in household and school populations serve as one of the primary sources of information about the distribution of illicit drug use. This research has demonstrated continued shifts in trends in illicit drug use in the United States and called attention to rising rates of prescription drug misuse and abuse. Findings have also continued to highlight the substantial comorbidity of SUDs with other psychiatric disorders and with the ongoing HIV epidemic. Building on these foundations, future challenges for research in substance abuse epidemiology will include using novel methodologic approaches to further unravel the complex interrelationships that link individual vulnerabilities for SUDs, including genetic factors, with social and environmental risk factors.

Field of study: Medicine, Psychology
Processes occurring during the formation of graded ZnSe/ZnTe contacts on p-ZnSe

We show that the formation of ohmic contacts to p-ZnSe does not mainly depend on the exact design of the applied ZnSe/ZnTe grading, but rather on the temperature during contact growth and the thickness of the ZnTe cap layer on top of the grading. These facts demonstrate that a diffusion process dominates the contact formation. From the activation energy of the diffusion process we conclude that the diffusing species is nitrogen, which diffuses from the ZnTe cap into the underlying p-ZnSe. The nitrogen excess leads to an overcompensation in the ZnSe. Such an overcompensation process can be quantitatively described by the formation of compensating complexes involving two nitrogen atoms.

Field of study: Materials science
Heat shock pretreatment induced cadmium resistance in the nematode Caenorhabditis elegans is depend on transcription factors DAF-16 and HSF-1.

Cadmium (Cd) exposure poses a serious environmental problem due to the metal's bioaccumulation and difficult to eliminate from body. Understanding the mechanisms of Cd detoxification and resistance can provide insights into methods to protect against the damaging effects of the heavy metal. In the present study, we found that heat shock (HS) pretreatment increased Cd resistance of the nematode Caenorhabditis elegans by reducing the bagging phenotype and protecting the integrity of the intestinal barrier. HS pretreatment increased the expression of heat shock protein-16.2 (HSP-16.2) prior to Cd exposure, and HS-induced Cd resistance was absent in worms with hsp-16.2 loss-of-function mutation. Worm strain with daf-2(e1370) mutation presented enhanced HS-induced Cd resistance, which was eliminated in worm strains of daf-16(mu86) and hsf-1(sy441). HS pretreatment increased DAF-16 nuclear localization and HSF-1 granule formation prior to Cd exposure. DAF-16 and HSF-1 was essential in reducing bagging formation and protecting the integrity of intestinal barrier after HS pretreatment. In conclusion, the present study demonstrated that HS-induced Cd resistance in C. elegans is regulated by the DAF-16/FOXO and HSF-1 pathways through regulation of HSP-16.2 expression.

Field of study: Environmental science
Dark Matter in Galaxies: Evidences and Challenges

The evidence of the phenomenon for which, in galaxies, the gravitating mass is distributed differently than the luminous mass, increases as new data become available. Furthermore, this discrepancy is well structured and it depends on the magnitude and the compactness of the galaxy and on the radius, in units of its luminous size $$R_{{ opt}}$$Ropt, where the measure is performed. For the disk systems with $$-13\ge M_I\ge -24$$-13≥MI≥-24 all this leads to an amazing scenario, revealed by the investigation of individual and coadded rotation curves, according to which, the circular velocity follows, from their centers out to their virial radii, an universal profile $$V_{{ URC}} (r/R_{{ opt}}, M_I)$$VURC(r/Ropt,MI) function only of the properties of the luminous mass component. Moreover, from the Universal Rotation Curve, so as from many individual high quality RCs, we discover that, in the innermost regions of galaxies, the DM halo density profiles are very shallow. Finally, the disk mass, the central halo density and its core radius, come out all related to each other and to two properties of the distribution of light in galaxies: the luminosity and the compactness. This phenomenology, being absent in the simplest $$\varLambda CDM$$ΛCDM Cosmology scenario, poses serious challenges to the latter or, alternatively, it requires a substantial and tuned involvement of baryons in the formation of the galactic halos. On the other side, the URC helps to explain the two-accelerations relationship found by McGaugh et al. ( 2016), in terms of only well known astrophysical processes, acting in a standard DM halos + luminous disks scenario.

Field of study: Physics