Fourfold Anisotropic Magnetoresistance of L1_{0} FePt Due to Relaxation Time Anisotropy.

Experimental measurements show that the angular dependence of the anisotropic magnetoresistance (AMR) in L1_{0} ordered FePt epitaxial films on the current orientation and magnetization direction is a superposition of the corresponding dependences of twofold and fourfold symmetries. The twofold AMR exhibits a strong dependence on the current orientation, whereas the fourfold term only depends on the magnetization direction in the crystal and is independent of the current orientation. First-principles calculations reveal that the fourfold AMR arises from the relaxation time anisotropy due to the variation of the density of states near the Fermi energy under rotation of the magnetization. This relaxation time anisotropy is a universal property in ferromagnetic metals and determines other anisotropic physical properties that are observable in experiment.

Depth-Resolved Magnetization Dynamics Revealed by X-Ray Reflectometry Ferromagnetic Resonance.

Magnetic multilayers offer diverse opportunities for the development of ultrafast functional devices through advanced interface and layer engineering. Nevertheless, a method for determining their dynamic properties as a function of depth throughout such stacks has remained elusive. By probing the ferromagnetic resonance modes with element-selective soft x-ray resonant reflectivity, we gain access to the magnetization dynamics as a function of depth. Most notably, using reflectometry ferromagnetic resonance, we find a phase lag between the coupled ferromagnetic layers in [CoFeB/MgO/Ta]_{4} multilayers that is invisible to other techniques. The use of reflectometry ferromagnetic resonance enables the time-resolved and depth-resolved probing of the complex magnetization dynamics of a wide range of functional magnetic heterostructures with absorption edges in the soft x-ray wavelength regime.

Temperature sensitive supramolecular self assembly of per-6-PEO-ß-cyclodextrin and α,ω-di-(adamantylethyl)poly(N-isopropylacrylamide) in water.

The host/guest interactions in water of a star polymer consisting of a ß-cyclodextrin (ß-CD) core bearing six poly(ethylene oxide) arms linked to the C6 positions of ß-CD (ß-CD-PEO7, Mn 5000 g mol(-1)) and α,ω-di-(adamantylethyl)poly(N-isopropylacrylamide) (Ad-PNIPAM-12K, Mn 12,000 g mol(-1)) were studied by 1D and 2D (1)H and (13)C NMR spectroscopy, isothermal calorimetry (ITC), and light scattering (LS). In cold water (T < 26 °C) supramolecular "dumbbell" assemblies, consisting of PNIPAM chains with ß-CD/Ad inclusion complexes at each end, formed viaß-CD-insertion of the terminal Ads through the ß-CD secondary face. Light scattering, microcalorimetry (DSC), and DOSY NMR studies indicated that mixed aqueous solutions of ß-CD-PEO7 and Ad-PNIPAM-12K undergo a reversible heat-induced phase transition at ∼32 °C, accompanied by a release of a fraction of the Ad-bound ß-CD-PEO7 into bulk solution and the formation of aggregated Ad-PNIPAM-12K stabilized by a ß-CD-PEO7 shell.

Genetic diversity of HLA-DRB1 alleles in the Tujia population of Wufeng, Hubei Province, China.

We established a genetic database by investigating human leukocyte antigen (HLA)-DRB1 allelic frequencies in a disease-association study in the Tujia population in Wufang, Hubei, China. The allele frequencies of the HLA-DRB1 locus in 262 healthy, unrelated Tujia individuals living in the Wufeng region of the Hubei Province were analyzed using the Luminex HLA sequence-specific oligonucleotide method with a WAKFlow HLA typing kit. A total of 13 alleles were detected at the HLA-DRB1 locus. HLA-DRB1*09 was the most common allele (22.52%), followed by DRB1*08 and DRB1*15 (11.07%), and DRB1*12 and DRB1*04 (10.69%). These data were compared with the results obtained for 10 other ethnic groups living in other regions as well as to Han groups using neighbor-joining dendrograms and principal component analysis. The results showed that the Tujia population has a close genetic relationship with the Middle Han population at the HLA-DRB1 locus. This information will be useful for HLA-DRB1-linked disease-association studies.

Large ultrafast-modulated Voigt effect in noncollinear antiferromagnet Mn3Sn.

The time-resolved magneto-optical (MO) Voigt effect can be utilized to study the Néel order dynamics in antiferromagnetic (AFM) materials, but it has been limited for collinear AFM spin configuration. Here, we have demonstrated that in Mn3Sn with an inverse triangular spin structure, the quench of AFM order by ultrafast laser pulses can result in a large Voigt effect modulation. The modulated Voigt angle is significantly larger than the polarization rotation due to the crystal-structure related linear dichroism effect and the modulated MO Kerr angle arising from the ferroic ordering of cluster magnetic octupole. The AFM order quench time shows negligible change with increasing temperature approaching the Néel temperature (TN), in markedly contrast with the pronounced slowing-down demagnetization typically observed in conventional magnetic materials. This atypical behavior can be explained by the influence of weakened Dzyaloshinskii-Moriya interaction rather than the smaller exchange splitting on the diminished AFM order near TN. The temperature-insensitive ultrafast spin manipulation can pave the way for high-speed spintronic devices either working at a wide range of temperature or demanding spin switching near TN.

Ambipolar ferromagnetism by electrostatic doping of a manganite.

Complex-oxide materials exhibit physical properties that involve the interplay of charge and spin degrees of freedom. However, an ambipolar oxide that is able to exhibit both electron-doped and hole-doped ferromagnetism in the same material has proved elusive. Here we report ambipolar ferromagnetism in LaMnO3, with electron-hole asymmetry of the ferromagnetic order. Starting from an undoped atomically thin LaMnO3 film, we electrostatically dope the material with electrons or holes according to the polarity of a voltage applied across an ionic liquid gate. Magnetotransport characterization reveals that an increase of either electron-doping or hole-doping induced ferromagnetic order in this antiferromagnetic compound, and leads to an insulator-to-metal transition with colossal magnetoresistance showing electron-hole asymmetry. These findings are supported by density functional theory calculations, showing that strengthening of the inter-plane ferromagnetic exchange interaction is the origin of the ambipolar ferromagnetism. The result raises the prospect of exploiting ambipolar magnetic functionality in strongly correlated electron systems.

[The correlation between the types of the uncinate process superiorattachment and chronic frontal sinusitis without nasal polyps].

Objective:To investigate the correlation between the types of unicate process (UP) superior attachment and the chronic frontal sinusitis without nasal polyps(CFSsNP).Method:The images of 240 sides of frontal recess were evaluated. The types of UP superior attachment was compared between the CFSsNP group and the control group. The correlation between UP the superior attachment and CFSsNP were analyzed. Result:Seven types of UP superior attachment were identified. The most common type in the two study groups was type 1(insertion into the lamina papyracea). The occurrence rate of type 1 of UP superior attachment in the CFSsNP group was significantly higher than that in the control group(59.8% and 36.4%,respectively P<0.01),but type 5(insertion into both the lamina papyracea and the skull base) was significantly less frequent in the CFSsNP group than in the control group(9.8%，28.8%,P<0.01). Logistic regression analysis revealed that the type 1 of UP superior attachment was an independent risk factor for CFSsNP(OR=1.181,P<0.05),and that type 5 of UP superior attachment was a protective factor for CFSsNP(OR=0.391,P<0.05). Conclusion:UP superior attachment varied significantly,with the most common type being type 1; This type is intimately related to CFSsNP.

[Evaluation of the frontal recess cells with image-guided system].

Objective:To investigate the value of image-guided system in identifying the frontal recess cells.Method:We collected 30 cases that underwent image-guided frontal sinus surgery from November 2014 to December 2015. These frontal recess cells were devided into 2 groups based upon their locations in the frontal sinus ostium. Group A consists of the agger nasi cells, type Ⅰfrontal cells, type Ⅱ frontal cells and suprabullar cells; group B consist of type Ⅲ frontal cells, type Ⅳ frontal cells, frontal bullar cells, interfrontal sinus septal cells and supraorbital ethmoid cells. Visual analogue scale (VAS) was used to evaluate the degree of demand of image guide system on the location of frontal recess cells, and then analyzed the value of image guided system on the frontal recess cells.Result:In all 30 patients the imageguided frontal sinus surgery was successfully completed.The demand degree of image-guided system on frontal recess cells by VAS was slight for the agger nasi cells, type Ⅰfrontal cells, type Ⅱ frontal cells and suprabullar cells; the demand degree was general for the frontal bullar cells and interfrontal sinus septal cells; the demand degree was obvious for type Ⅲ frontal cells, type Ⅳ frontal cells and supraorbital ethmoid cells. Frontal recess cells of group B were more depended on image guided system than those of group A, and the difference was signicant(P <0.01).Conclusion:Imageguided system is valuable in distinguishing for type Ⅲ frontal cells,type Ⅳ frontal cells supraorbital ethmoid cells and interfrontal sinus septal cells.Furthermore,it is significantly helpful for accurate removal of these frontal recess cells in endoscopic frontal sinus surgery.

[Origin and differentiation of domestic goose breeds in China, inferred from mitochondrial DNA polymorphism].

Mitochondrial DNAs (mtDNAs) of 138 samples from 11 domestic goose breeds in China were investigated by digesting, with 19 restriction endonucleases. Of 19 enzymes used, seven (Bcl I, Dra I, Eco RV, Hae II, Hinc II, Kpn I, Sac I) detected polymorphic patterns. By combining 27 restriction morphs, 138 individuals were classified into 6 mtDNA haplotypes. Phylogenetic tree was constructed by using UPGMA. There was no shared haplotype between Yili breed and the other 10 breeds. Genetic distance and UPGMA tree also suggested that Yili breed and other breeds came from different ancestors. Yili breed originated from Anser anser and other 10 breeds originated from Anser cygnoides. Restriction morphs digested with 4 enzymes (EcoRV, Hae II, Hinc II and Kpn I) could be used as maternal genetic markers to distinguish the two types of domestic geese. Mitochondrial DNA polymorphism was observed in the ten breeds of Anser cygnoides. Nucleotide diversity (pi), genetic distance between the two types and the average genetic distance among the ten breeds were estimated to be 0.025%, 0.266%, 0.029%, respectively. The breeds with white plume were affected by founder effect when they were formed. Swan domestic geese, Anser cygnoides domesticus, in China might come from two different populations of Anser cygnoides at two different places.

Dual silencing of type 1 insulin-like growth factor and epidermal growth factor receptors to induce apoptosis of nasopharyngeal cancer cells.

OBJECTIVE: The epidermal growth factor receptor (EGFR) and type 1 insulin-like growth factor receptor (type 1 IGF receptor or IGF1R) have played an important role in the growth and apoptosis of cancer. The RNA interference (RNAi) technique can suppress gene expression, but the effects of dual silencing of EGFR and type 1 IGF receptor have not been well understood. METHODS: pU6-EGFR-shRNA-1, pU6-EGFR-shRNA-2, pU6-IGF1R-shRNA-1 and pU6-IGF-1R-shRNA-2 plasimd vectors were transfected to the nasopharyngeal cancer cells. Seven groups were selected for the study. The protein and downstream protein expression were assessed by Western blot. Apoptosis was determined via flow cytometry. Meanwhile, chemosensitivity of nasopharyngeal cancer cell lines transfeced to chemotherapeutic drugs were carried out by MTT. RESULTS: In dual silencing of EGFR and IGF-1R, the protein expression much more was decreased than single silencing of EGFR or IGF-1R, but the cell apoptosis much more is increased than single silencing EGFR or IGF-1R. Dual silencing of EGFR and IGF-1R enhanced chemosensitivity to anticancer drugs, compared with single silencing of EGFR or IGF-1R. CONCLUSION: Dual silencing of EGFR and IGF-1R are capable of suppressing EGFR and IGF-1R expression of the nasopharyngeal cancer cell and can promote apoptosis and increase the cell sensitivity of anticancer drug. The dual silencing of genes RNAi technique is significantly better than a single gene.

Rotation of the pinning direction in the exchange bias training effect in polycrystalline NiFe/FeMn bilayers.

For polycrystalline NiFe/FeMn bilayers, we have observed and quantified the rotation of the pinning direction in the exchange bias training and recovery effects. During consecutive hysteresis loops, the rotation of the pinning direction strongly depends on the magnetization reversal mechanism of the ferromagnet layer. The interfacial uncompensated magnetic moment of antiferromagnetic grains may be irreversibly switched and rotated when the magnetization reversal process of the ferromagnet layer is accompanied by domain wall motion and domain rotation, respectively.

Mitochondrial DNA cleavage patterns distinguish independent origin of Chinese domestic geese and Western domestic geese.

It has generally been assumed, based on morphology, that Chinese domestic goose breeds were derived from the swan goose (Anser cygnoides) and that European and American breeds were derived from the graylag goose (Anser anser). To test the validity of this assumption, we investigated the mtDNA cleavage patterns of 16 Chinese breeds and 2 European breeds as well as hybrids produced between a Chinese breed and a European breed. After 224 mtDNAs, isolated from the Chinese and European breeds, were digested by 19 restriction endonucleases, variations of the cleavage patterns were observed for four enzymes (EcoRV, HaeII, HincII, and KpnI). All Chinese breeds and their maternal hybrids except the Yili breed showed an identical haplotype, named haplotype I or the Chinese haplotype; the European breeds and the Yili breed showed another haplotype, named haplotype II or the western haplotype. None of the haplotype found in the Chinese type was detectable in the western type and vice versa. The two haplotypes were found to differ from each other at 8.0% of the sites surveyed and with a 0.72% sequence divergence. Using 2% substitution per million years calibrated from the genera Anser and Branta, the two domestic geese haplotypes were estimated to have diverged approximately 360,000 years ago, well outside the 3000-6000 years in domestic history. Our findings provide the first molecular genetic evidence to support the dual origin assumption of domestic geese in the world. Meanwhile, the four mtDNA restriction fragment length polymorphisms can be used as maternal genetic markers to distinguish the two types of domestic geese.

Origin of rabbit (Oryctolagus cuniculus) in China: evidence from mitochondrial DNA control region sequence analysis.

A fragment of mitochondrial DNA (mtDNA) control region (approximately 700 bp) was sequenced in 104 individuals from 20 breeds (three Chinese domestic breeds, five recently derived breeds and 12 introduced breeds) of domestic rabbits, Oryctolagus cuniculus. Nineteen sites were polymorphic, with 18 transitions and one insertion/deletion, and eight haplotypes (A1, A2, A3, A4, A5, A6, A7 and A8) were identified. Haplotype A1 was the most common and occurred in 89 individuals. In the 25 Chinese rabbits, only haplotype A1 was observed, while four haplotypes (A1, A3, A5 and A6) were found in 26 recently derived individuals. Haplotype A2 was shared by seven individuals among three introduced strains. The other six haplotypes accounted for 0.96-1.92% of the animals. Combined with the published sequences of European rabbits, a reduced median-joining network was constructed. The Chinese rabbit mtDNAs were scattered into two clusters of European rabbits. These results suggest that the (so-called) Chinese rabbits were introduced from Europe. Genetic diversity in Chinese rabbits was very low.