Novel Predictors of Stroke-Associated Pneumonia: A Single Center Analysis.

Stroke-associated pneumonia (SAP) is a common cause of disability or death. Although the researches on SAP have been relatively mature, the method that can predict SAP with great accuracy has not yet been determined. It is necessary to discover new predictors to construct a more accurate predictive model for SAP. We continuously collected 2,366 patients with acute ischemic stroke, and then divided them into the SAP group and non-SAP group. Data were recorded at admission. Through univariate analyses and multivariate regression analyses of the data, the new predictive factors and the predictive model of SAP were determined. The receiver operating characteristic (ROC) curve and the corresponding area under the curve (AUC) were used to measure their predictive accuracy. Of the 2,366 patients, 459 were diagnosed with SAP. International normalized ratio (INR) (odds ratio = 37.981; 95% confidence interval, 7.487-192.665; P < 0.001), age and dysphagia were independent risk factors of SAP. However, walking ability within 48 h of admission (WA) (odds ratio = 0.395; 95% confidence interval, 0.287-0.543; P < 0.001) was a protective factor of SAP. Different predictors and the predictive model all could predict SAP (P < 0.001). The predictive power of the model (AUC: 0.851) which included age, homocysteine, INR, history of chronic obstructive pulmonary disease (COPD), dysphagia, and WA was greater than that of age (AUC: 0.738) and INR (AUC: 0.685). Finally, we found that a higher INR and no WA could predict SAP in patients with acute ischemic stroke. In addition, we designed a simple and practical predictive model for SAP, which showed relatively good accuracy. These findings might help identify high-risk patients with SAP and provide a reference for the timely use of preventive antibiotics.

Cyclodextrin-driven movement of cucurbit[7]uril.

The movement of cucurbit[7]uril (CB[7]) driven by alpha-cyclodextrin (alpha-CD) is investigated by various experimental techniques including NMR, ESI-MS, UV-vis, and ITC. CB[7] can form stable pseudorotaxanes with N-methyl-N'-octyl-4,4'-bipyridinium (MVO2+) and N,N'-dioctyl-4,4'-bipyridinium (OV2+) dication in aqueous solution. CB[7] shuttles between the octyl and bipyridinium moieties in MVO2+, but docks at one of the octyl moieties in OV2+. The addition of alpha-CD pushes CB[7] from the octyl moiety of MVO2+ or OV2+ to the bipyridinium moiety. Thermodynamically, the movement of CB[7] is mainly driven by exothermic enthalpy changes coming from the complexation of the octyl moiety of MVO2+ or OV2+ with alpha-CD.

A chromophoric switch based on pseudorotaxanes.

In a three-component system containing dibenzo-24-crown-8 (1), diamino-dibenzo-24-crown-8 (2), and 1,2-bis(4,4(')-dipyridyl)ethane (3(2+)), axle 3(2+) can shuttle between wheels 1 and 2 by acid-base control, accompanying color changes from yellow to red. This system could not only be taken as a chromophoric supramolecular switch, but also exhibit a function as INHIBIT logic gate.

A multifunctional arithmetical processor model integrated inside a single molecule.

Improving the processing power of molecules remains the challenge for molecular logic and computation. Here we report a 2-phenylimidazo[4,5-f][1,10]phenanthroline (PIPH)-based three-state molecular switch by controlling its unique emission and absorption spectra in the acid and base condition. On one hand, PIPH can perform simultaneously the functions of an "AND" gate and an "XOR" gate, capable of operating as a half-adder, and the "off-on-off" function as well as comparison function by monitoring its fluorescent spectral changes. On the other hand, the molecule can also implement in parallel the functions of an "XOR" gate and two "INH" gates by monitoring its absorption spectral changes, which constructs two half-subtractors. The cooperative operation of comparator and half-subtractor makes general subtraction operation become possible, which is discussed conceptually in the report.

Unique conformation and packing structure of p-sulfonatocalix[5]arene induced by 1,2-bis(pyridinium)ethane compounds.

In the presence of 1,2-bis(4,4'-dipyridinium)ethane, p-sulfonatocalix[5]arene (C5AS) adopts an unseen partial-cone conformation to form back-to-back dimers, whereas C5AS crystallizes in face-to-face dimers to form a wavy layer, rather than the expected bilayer, arrangement upon complexation with 1,2-bis(pyridinium)ethane.

Diastereoisomer-selective inclusion complexation of Cinchona alkaloids with a modified beta-cyclodextrin: fluorescent behavior enhanced by chiral-tether binding. Short communication.

The molecular 1:1 complexation of cinchona alkaloids by mono(6-deoxy-6-{[(R)-1-(hydroxymethyl)propyl]amino})-beta-cyclodextrin (1) in aqueous solution has been investigated by 2D-NMR, fluorescence titration, and fluorescence-lifetime experiments. Generally, with 1 as the host, in contrast to beta-cyclodextrin proper, strong binding of quinine (2; Ka = 84,200 M(-1)) and quinidine (3; Ka = 27,300 M(-1)) at pH 6.8 was observed, as monitored by an increase in fluorescence intensity, with a fair degree of diastereoisomer discrimination (ca. 3:1). To rationalize these results, two possible cooperative complexation modes, including specific H-bonding interactions to the chiral tether of the cyclodextrin portion, are proposed.