Variation in Interleukin 6 Receptor Gene Associates with Risk of Crohn’s Disease and Ulcerative Colitis

Interleukin 6 (IL6) is an inflammatory cytokine; signaling via its receptor (IL6R) is believed to contribute to development of inflammatory bowel diseases (IBD). The single nucleotide polymorphism rs2228145 in IL6R associates with increased levels of soluble IL6R (s-IL6R), as well as reduced IL6R signaling and risk of inflammatory disorders; its effects are similar to those of a therapeutic monoclonal antibody that blocks IL6R signaling. We used the effect of rs2228145 on s-IL6R level as an indirect marker to investigate whether reduced IL6R signaling associates with risk of ulcerative colitis (UC) or Crohn’s disease (CD). In a genome-wide meta-analysis of 20,550 patients with CD, 17647 patients with UC, and more than 40,000 individuals without IBD (controls), we found that rs2228145 (scaled to a 2-fold increase in s-IL6R) was associated with reduced risk of CD (odds ratio, 0.876; 95% CI, 0.822–0.933; P=.00003) or UC (odds ratio, 0.932; 95% CI, 0.875–0.996; P=.036). These findings indicate that therapeutics designed to block IL6R signaling might be effective in treatment of IBD

An unexpected cubic symmetry in group IV alloys prepared using pressure and temperature

The cubic diamond (Fd-3m) group IVA element Si has been the material driver of the electronics industry since its inception. We report synthesis of a new cubic (Im-3m) group IVA material, a GeSn solid solution, upon heating Ge and Sn at pressures from 13 to 28 GPa using double-sided diamond anvil laser-heating and large volume press methods. Both methods were coupled with in-situ angle dispersive X-ray diffraction characterization. The new material substantially enriches the seminal group IVA alloy materials landscape by introducing an eightfold coordinated cubic symmetry, which markedly expands on the conventional tetrahedrally coordinated cubic one. This cubic solid solution is formed, despite Ge never adopting the Im-3m symmetry, melting inhibiting subsequent Im-3m formation and reactant Ge and Sn having unlike crystal structures and atomic radii at all these pressures. This is hence achieved without adherence to conventional formation criteria and routes to synthesis. This advance creates fertile avenues for new materials development

Unconventional Route to High-Pressure and -Temperature Synthesis of GeSn Solid Solutions

Ge and Sn are unreactive at ambient conditions. Their significant promise for optoelectronic applications is thus largely confined to thin film investigations. We sought to remove barriers to reactivity here by accessing a unique pressure, 10 GPa, where the two elements can adopt the same crystal structure (tetragonal, $I4_1$/$amd$) and exhibit compatible atomic radii. The route to GeSn solid solution, however, even under these directed conditions, is different. Reaction upon heating at 10 GPa occurs between unlike crystal structures (Ge, $Fd3m$ and Sn, $I$4/$mmm$), which also have highly incompatible atomic radii. They should not react, but they do. A reconstructive transformation of $I$4/$mmm$ into the $I$4$_1$/$amd$ solid solution then follows. The new tetragonal GeSn solid solution ($I$4$_1$/$amda$ = 5.280(1) Å, c = 2.915(1) Å, Z = 4 at 9.9 GPa and 298 K) also constitutes the structural and electronic bridge between 4-fold and newly prepared 8-fold coordinated alloy cubic symmetries. Furthermore, using this high-pressure route, bulk cubic diamond-structured GeSn alloys can now be obtained at ambient pressure. The findings here remove confining conventional criteria on routes to synthesis. This opens innovative avenues to advanced materials development

Hexagonal Si-Ge Class of Semiconducting Alloys Prepared Using Pressure and Temperature

Multi-anvil and laser-heated diamond anvil methods have been used to subject Ge and Si mixtures to pressures and temperatures of between 12 and 17 GPa and 1500–1800 K, respectively. Synchrotron angle dispersive X-ray diffraction, precession electron diffraction and chemical analysis using electron microscopy, reveal recovery atambient pressure of hexagonal Ge-Si solid solutions (P6$_3$/mmc). Taken together, the multi-anvil and diamond anvil results reveal that hexagonal solid solutions can be preparedfor all Ge-Si compositions. This hexagonal class of solid solutions constitutes a significant expansion of the bulk Ge-Sisolid solution family, and is of interest for optoelectronic applications

Synthesis and high-resolution study distinguishing between very similar interstitial iron nitride structures

International audienc

Unconventional Route to High-Pressure and -Temperature Synthesis of GeSn Solid Solutions

Ge and Sn are unreactive at ambient conditions. Their significant promise for optoelectronic applications is thus largely confined to thin film investigations. We sought to remove barriers to reactivity here by accessing a unique pressure, 10 GPa, where the two elements can adopt the same crystal structure (tetragonal, $I4_1$/$amd$) and exhibit compatible atomic radii. The route to GeSn solid solution, however, even under these directed conditions, is different. Reaction upon heating at 10 GPa occurs between unlike crystal structures (Ge, $Fd3m$ and Sn, $I$4/$mmm$), which also have highly incompatible atomic radii. They should not react, but they do. A reconstructive transformation of $I$4/$mmm$ into the $I$4$_1$/$amd$ solid solution then follows. The new tetragonal GeSn solid solution ($I$4$_1$/$amda$ = 5.280(1) Å, c = 2.915(1) Å, Z = 4 at 9.9 GPa and 298 K) also constitutes the structural and electronic bridge between 4-fold and newly prepared 8-fold coordinated alloy cubic symmetries. Furthermore, using this high-pressure route, bulk cubic diamond-structured GeSn alloys can now be obtained at ambient pressure. The findings here remove confining conventional criteria on routes to synthesis. This opens innovative avenues to advanced materials development

Creating Reactivity with Unstable Endmembers using Pressure and Temperature: Synthesis of Bulk Cubic Mg0.4Fe0.6N

International audienc