High hardness in the biocompatible intermetallic compound ß-Ti3Au.

The search for new hard materials is often challenging, but strongly motivated by the vast application potential such materials hold. Ti3Au exhibits high hardness values (about four times those of pure Ti and most steel alloys), reduced coefficient of friction and wear rates, and biocompatibility, all of which are optimal traits for orthopedic, dental, and prosthetic applications. In addition, the ability of this compound to adhere to ceramic parts can reduce both the weight and the cost of medical components. The fourfold increase in the hardness of Ti3Au compared to other Ti-Au alloys and compounds can be attributed to the elevated valence electron density, the reduced bond length, and the pseudogap formation. Understanding the origin of hardness in this intermetallic compound provides an avenue toward designing superior biocompatible, hard materials.

[The capacity of proliferation and migration is higher in Tca8113 cells with up-regulated TNFSF14 expression].

OBJECTIVE: To construct a lentiviral vector carrying tumor necrosis factor superfamily member 14 (TNFSF14) gene, infect tongue cancer Tca8113 cells in vitro, and observe the effect on infected Tca8113 cells. METHODS: A lentiviral vector containing TNFSF14 gene was constructed and used to infect the Tca8113 cells. After selected by puromycin, the level of TNFSF14 mRNA in Tca8113 cells was detected by real-time quantitative PCR. Cell proliferation activity and cell circle were determined respectively by MTT assay and flow cytometry (FCM). And the cell migration ability was measured by Transwell(TM) assay. RESULTS: Compared with the control group, the expression of TNFSF14 mRNA increased in the infected cells. MTT assay and FCM showed TNFSF14 promoted the proliferation of Tca8113 cells. Transwell™ assay showed TNFSF14 boosted the migration ability of Tca8113 cells. CONCLUSION: The proliferation and migration would be enhanced in Tca8113 cells with over-expressed TNFSF14.

An itinerant antiferromagnetic metal without magnetic constituents.

The origin of magnetism in metals has been traditionally discussed in two diametrically opposite limits: itinerant and local moments. Surprisingly, there are very few known examples of materials that are close to the itinerant limit, and their properties are not universally understood. In the case of the two such examples discovered several decades ago, the itinerant ferromagnets ZrZn2 and Sc3In, the understanding of their magnetic ground states draws on the existence of 3d electrons subject to strong spin fluctuations. Similarly, in Cr, an elemental itinerant antiferromagnet with a spin density wave ground state, its 3d electron character has been deemed crucial to it being magnetic. Here, we report evidence for an itinerant antiferromagnetic metal with no magnetic constituents: TiAu. Antiferromagnetic order occurs below a Néel temperature of 36 K, about an order of magnitude smaller than in Cr, rendering the spin fluctuations in TiAu more important at low temperatures. This itinerant antiferromagnet challenges the currently limited understanding of weak itinerant antiferromagnetism, while providing insights into the effects of spin fluctuations in itinerant-electron systems.

Effects of ginsenoside Rg-1 on the proliferation and osteogenic differentiation of human periodontal ligament stem cells.

OBJECTIVE: To evaluate the effects of ginsenoside Rg-1 on the proliferation and osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) and to explore the possible application on the alveolar bone regeneration. METHODS: To determine the optimum concentration, the effects of ginsenoside Rg-1 ranging from 10 to 100 µmol/L were evaluated by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide, alkaline phosphatase activity and calcium deposition. Expressions of runt-related transcription factor 2, collagen alpha-2(I) chain, osteopontin, osteocalcin protein were examined using real-time polymerase chain reaction. RESULTS: Compared with the control group, a certain concentration (10 µmol/L) of the Rg-1 solution significantly enhanced the proliferation and osteogenic differentiation of hPDLSCs (P<0.05). However, concentrations that exceeds 100 µmol/L led to cytotoxicity whereas concentrations below 10 nmol/L showed no significant effect as compared with the control. CONCLUSION: Ginsenoside Rg-1 can enhance the proliferation and osteogenic differentiation of hPDLSCs at an optimal concentration of 10 µmol/L.

Discovery of spin glass behavior in Ln2Fe4Sb5 (Ln = La-Nd and Sm).

Single crystals of Ln(2)Fe(4)Sb(5) (Ln = La-Nd and Sm) were grown from an inert Bi flux. Measurements of the single crystal X-ray diffraction revealed that these compounds crystallize in the tetragonal space group I4/mmm with lattice parameters of a ≈ 4 Å, c ≈ 26 Å, V ≈ 500 Å(3), and Z = 2. This crystal structure consists of alternating LnSb(8) square antiprisms and Fe-sublattices composed of nearly equilateral triangles of bonded Fe atoms. These compounds are metallic and display spin glass behavior, which originates from the magnetic interactions within the Fe-sublattice. Specific heat measurements are void of any sharp features that can be interpreted as contributions from phase transitions as is typical for spin glass systems. A large, approximately linear in temperature, contribution to the specific heat of La(2)Fe(4)Sb(5) is observed at low temperatures that we interpret as having a magnetic origin. Herein, we report the synthesis, structure, and physical properties of Ln(2)Fe(4)Sb(5) (Ln = La-Nd and Sm).

Synthesis, structure, and physical properties of Ln(Cu,Al,Ga)(13-x) (Ln = La-Pr, and Eu) and Eu(Cu,Al)(13-x).

Ln(Cu,Al,Ga)(13-x) (Ln = La-Pr, and Eu; x ~ 0.2) were synthesized by a combined Al/Ga flux. Single crystal X-ray and neutron diffraction experiments revealed that these compounds crystallize in the NaZn(13) structure-type (space group Fm3[overline]c) with lattice parameters of a ~ 12 Å, V ~ 1600 Å, and Z ~ 8. Our final neutron models led us to conclude that Cu is occupationally disordered on the 8b Wyckoff site while Cu, Al, and Ga are substitutionally disordered on the 96i Wyckoff site of this well-known structure-type. The magnetic susceptibility data show that Ce(Cu,Al,Ga)(13-x) and Pr(Cu,Al,Ga)(13-x) exhibit paramagnetic behavior down to the lowest temperatures measured while Eu(Cu,Al,Ga)(13-x) displays ferromagnetic behavior below 6 K. Eu(Cu,Al)(13-x) was prepared via arc-melting and orders ferromagnetically below 8 K. The magnetocaloric properties of Eu(Cu,Al,Ga)(13-x) and Eu(Cu,Al)(13-x) were measured and compared. Additionally, an enhanced value of the Sommerfeld coefficient (γ = 356 mJ/mol-K(2)) was determined for Pr(Cu,Al,Ga)(13-x). Herein, we present the synthesis, structural refinement details, and physical properties of Ln(Cu,Al,Ga)(13-x) (Ln = La-Pr, and Eu) and Eu(Cu,Al)(13-x).

Crystal growth, structure, and physical properties of LnCu2(Al,Si)5 (Ln = La and Ce).

LnCu(2)(Al,Si)(5) (Ln = La and Ce) were synthesized and characterized. These compounds adopt the SrAu(2)Ga(5) structure type and crystallize in the tetragonal space group P4/mmm with unit cell dimensions of a ≈ 4.2 Å and c ≈ 7.9 Å. Herein, we report the structure as obtained from single crystal X-ray diffraction. Additionally, we report the magnetic susceptibility, magnetization, resistivity, and specific heat capacity data obtained for polycrystalline samples of LnCu(2)(Al,Si)(5) (Ln = La and Ce).

[The duration and amount of fire (huo hou) in drug processing].

The unique connotations for the special terms such as slow fire (wen huo), strong fire (wu huo), moderate fire (wen wu huo), ma tong fire, husk fire (kang huo), reed fire (lu di huo), mulberry fire (sang cai huo) and charcoal fire (tan huo) are investigated. There are many practical examples of these terms in related literature. The drug process is related to the alchemy in Taoism. The methods of fire control in drug processing are mostly from the literature on Alchemy (dan jing). The expression of these special terms and their connotations are different in various literature, because of their different traditions.

[Comparative studies on purgative potency among three spieces of certified rhubarb].

OBJECTIVE: To investigate the difference and causes of purgative activity in three species of certified rhubarb, so as to lay steady foundations of further research on assessing purgative activity impersonally by using measurable indexes. METHOD: The potencies of three species were comparied with purgative ED, of mice as quantitative index which were calculated, and activities of Na+ K + -ATP ase in mouse colonic epithelial cell membrane were also investigated . The related purgative contents (conjunct and free rhein, chrysophanol, chrysophanic acid, sennoside A) were detected by HPLC and contents (total anthraquinones, anthraglucosennin; conjunct and free anthraquinones) were detected by UV. RESULT: There were different purgative activities among three spieces of certified rhubarb. Each purgative ED, of mice was Rheum tanguticum ( ED50 = 0. 37 g x kg (-1)) , R. officinale ( ED50 = 0. 99 g x kg(-1) ) and R. palrnatum from Gansu (ED50 = 1. 83 g x kg(-1)) , the ratio of potency of those was 4. 94: 1. 85: 1. In the meanwhile, the difference of the inhibitory effect on Na+ -K + -ATP ase in mouse colonic epithelial cell membrane and relative purgative components also existed in the three species of certified rhubarb. CONCLUSION: It disclosed that there was notable diference of purgative activity and components among three spieces of certified Rhubarb, which probably resulted in the ultimate diference in clinical prescription and the production of Chinese patent medicines.

[Herbalogical textual study on "guanzhong"].

Herbalogical textual study indicated "Guanzhong" recorded in Bencaojing at Han Dynasty had pteridophyte characters. In the period of Wei and Jin Dynasties, the name of "Guanzhong" was really belonged to spermatophyte. Since Southern and Northern Dynasties, fern has been the main source of "Guanzhong" in which Woowardia japonica was used longer than others.