A New Group of Two-Dimensional Non-van der Waals Materials with Ultra Low Exfoliation Energies

The exfoliation energy - quantifying the energy required to extract a two-dimensional (2D) sheet from the surface of a bulk material - is a key parameter determining the synthesizability of 2D compounds. Here, using ab initio calculations, we present a new group of non-van der Waals 2D materials derived from non-layered crystals which exhibit ultra low exfoliation energies. In particular for sulfides, surface relaxations are essential to correctly describe the associated energy gain needed to obtain reliable results. Taking into account long-range dispersive interactions has only a minor effect on the energetics and ultimately proves that the exfoliation energies are close to the ones of traditional van der Waals bound 2D compounds. The candidates with the lowest energies, 2D SbTlO$_3$ and MnNaCl$_3$, exhibit appealing electronic, potential topological, and magnetic features as evident from the calculated band structures making these systems an attractive platform for fundamental and applied nanoscience.Comment: 23 pages, 14 figure

C-1 Root Schwannoma with Aggressive Lateral Mass Invasion

Schwannomas are relatively common, benign tumors that are thought to arise from the nerve sheath cell. Schwannomas of the C1 root are extremely rare and seldom invade lateral masses because they gradually increase in size and can extend through the wide space behind the lateral mass instead of the intervertebral foramen. We present here an unusual case of a benign schwannoma that aggressively invaded the lateral mass of C-1

Ethnic disparities in the risk of colorectal adenomas associated with aspirin and statin use: a retrospective multiethnic study

BACKGROUND: Although data on the inverse association between colorectal adenomas (CRA) and daily aspirin or statin therapy exists in white and black patients, scarce data exists on these associations in the Hispanic population. With a rapidly increasing Hispanic population in the United States, defining the association in Hispanics is crucial. METHODS: The study sample included 1,843 consecutive patients who underwent a colonoscopy (screening or diagnostic) from 2009 to 2011 at a community hospital in East Meadow, New York. Data was then extracted from patient charts regarding aspirin and/or statin use. Adjusted odds ratios (OR) and their 95% confidence intervals (CI) were calculated to assess the association between colonoscopy findings and aspirin, statin, or aspirin/statin use. RESULTS: In our total population including all races, aspirin user had an increased risk for having two or more adenomas (OR =1.73, 95% CI: 1.00, 2.99, P=0.05) and presence of an adenoma in the proximal colon (OR =1.66, 95% CI: 1.07, 2.58, P=0.02). In the total study population, those who used both statin and aspirin had an increased risk for having two or more adenomas (OR =2.56, 95% CI: 1.21, 5.39, P=0.01). In the Hispanic population, users of both medications had an increased risk for having two or more adenomas (OR =19.04, 95% CI: 1.30, 280.09, P=0.03), adenoma present in the distal colon (OR =5.75, 95% CI: 1.64, 20.21, P=0.01) and largest adenoma in distal colon (OR =5.75, 95% CI: 1.64, 20.21, P=0.01). CONCLUSIONS: Aspirin use and aspirin/statin use was associated with abnormal colonoscopy findings, particularly in the Hispanic population. These findings may be due to environmental factors such as dietary, colonic flora, or genetic susceptibility. The findings warrant further investigational research, particularly in Hispanics