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The calixarenes, 5,17-di­bromo-26,28-dihy­droxy-25,27-dipropynyloxycalix[4]arene (C34H26Br2O4, 1), 5,17-di­bromo-26,28-dipropoxy-25,27-dipropynyloxycalix[4]arene (C40H38Br2O4, 2) and 25,27-bis­(2-azido­eth­oxy)-5,17-di­bromo-26,28-di­hydroxy­calix[4]arene (C32H28Br2N6O4, 3) possess a pinched cone mol­ecular shape for 1 and 3, and a 1,3-alternate shape for compound 2. In calixarenes 1 and 3, the cone conformations are additionally stabilized by intra­molecular O—H⋯O hydrogen bonds, while in calixarene 2 intra­molecular Br⋯Br inter­actions consolidate the 1,3-alternate mol­ecular conformation. The dense crystal packing of the cone dialkyne 1 is a consequence of π–π, C—H⋯π and C—H⋯O inter­actions. In the crystal of the diazide 3, there are large channels extending parallel to the c axis, which are filled by highly disordered CH2Cl2 solvent mol­ecules. Their contribution to the intensity data was removed by the SQUEEZE procedure that showed an accessible void volume of 585 ų where there is room for 4.5 CH2Cl2 solvent mol­ecules per unit cell. Rigid mol­ecules of the 1,3-alternate calixarene 2 form a columnar head-to-tail packing parallel to [010] via van der Waals inter­actions, and the resulting columns are held together by weak C—H⋯π contacts. [ABSTRACT FROM AUTHOR]

Background: The high mortality rate of patients with acute myocardial infarction (AMI) remains the most pressing issue of modern cardiology. Over the past 10 years, there has been no significant reduction in mortality among patients with AMI. It is quite obvious that there is an urgent need to develop fundamentally new drugs for the treatment of AMI. Angiotensin 1–7 has some promise in this regard. Objective: The objective of this article is analysis of published data on the cardioprotective properties of angiotensin 1–7. Methods: PubMed, Scopus, Science Direct, and Google Scholar were used to search articles for this study. Results: Angiotensin 1–7 increases cardiac tolerance to ischemia/reperfusion and mitigates adverse remodeling of the heart. Angiotensin 1–7 can prevent not only ischemic but also reperfusion cardiac injury. The activation of the Mas receptor plays a key role in these effects of angiotensin 1–7. Angiotensin 1–7 alleviates Ca2+ overload of cardiomyocytes and reactive oxygen species production in ischemia/reperfusion (I/R) of the myocardium. It is possible that both effects are involved in angiotensin 1–7‐triggered cardiac tolerance to I/R. Furthermore, angiotensin 1–7 inhibits apoptosis of cardiomyocytes and stimulates autophagy of cells. There is also indirect evidence suggesting that angiotensin 1–7 inhibits ferroptosis in cardiomyocytes. Moreover, angiotensin 1–7 possesses anti‐inflammatory properties, possibly achieved through NF‐kB activity inhibition. Phosphoinositide 3‐kinase, Akt, and NO synthase are involved in the infarct‐reducing effect of angiotensin 1–7. However, the specific end‐effector of the cardioprotective impact of angiotensin 1–7 remains unknown. Conclusion: The molecular nature of the end‐effector of the infarct‐limiting effect of angiotensin 1–7 has not been elucidated. Perhaps, this end‐effector is the sarcolemmal KATP channel or the mitochondrial KATP channel. [ABSTRACT FROM AUTHOR]

The calixarenes, 5,17-dibromo-26,28-dihydroxy-25,27-dipropynyloxycalix[4]- arene (C34H26Br2O4, 1), 5,17-dibromo-26,28-dipropoxy-25,27-dipropynyloxycalix[4]arene (C40H38Br2O4, 2) and 25,27-bis(2-azidoethoxy)-5,17-dibromo-26,28-dihydroxycalix[4]arene (C32H28Br2N6O4, 3) possess a pinched cone molecular shape for 1 and 3, and a 1,3-alternate shape for compound 2. In calixarenes 1 and 3, the cone conformations are additionally stabilized by intra-molecular O-H⋯O hydrogen bonds, while in calixarene 2 intra-molecular Br⋯Br inter-actions consolidate the 1,3-alternate mol-ecular conformation. The dense crystal packing of the cone dialkyne 1 is a consequence of π-π, C-H⋯π and C-H⋯O inter-actions. In the crystal of the diazide 3, there are large channels extending parallel to the c axis, which are filled by highly disordered CH2Cl2 solvent mol-ecules. Their contribution to the intensity data was removed by the SQUEEZE procedure that showed an accessible void volume of 585 Å3 where there is room for 4.5 CH2Cl2 solvent mol-ecules per unit cell. Rigid mol-ecules of the 1,3-alternate calixarene 2 form a columnar head-to-tail packing parallel to [010] via van der Waals inter-actions, and the resulting columns are held together by weak C-H⋯π contacts. [ABSTRACT FROM AUTHOR]

Background/Context: The establishment of community colleges in the American states stands as one of the most unique features of our system of postsecondary education. Four possible explanations have been suggested for the growth of community colleges. An economic perspective argues that the development of community colleges came about as a result of increased demand. The sociological perspective argues that these institutions were developed as a result of broader social forces. The political science literature focuses on the role of lobbying and constituent demands. The organizational ecology literature suggests that community colleges fill a unique niche. Purpose/Objective/Research Question/Focus of Study: We seek to understand why certain states created large systems of community colleges, whereas other states developed few or none of these institutions. Research Design: We test theories from the literature using a multilevel Poisson regression model, using Bayesian methods for estimation and inference. Data Collection and Analysis: The data for this study come from a unique data set, compiled from a variety of sources of state-level data. The data cover all 50 states for the years 1969-2002. We estimate four models: a complete-pooling model with no unit-specific controls, a no-pooling model with controls for each state, a partial pooling model that allows state effects to vary, and a partial pooling model with a state-specific time trend. Findings/Results: Our results indicate support for the idea that community colleges grew in response to changes in state populations and that states with a large number of other types of institutions of higher education saw slower growth. Little support is found for theories regarding community colleges as engines of stratification. Conclusions/Recommendations: This study provides support for the idea that the supply of higher education institutions is responsive to demand. Little support is found for the role of social stratification in the development of new institutions. Political forces do appear to play at least a small role in the expansion of institutions. Existing institutions may slow the growth of newer forms of postsecondary education.