Controllable transmission of vector beams in dichroic medium

Vector beams with spatially varying polarization distribution in the wavefront plane have received increasing attention in recent years. The manipulation of vector beams both in intensity and polarization distributions is highly desired and under development. In this work, we study the transmission property of vector beams through warm rubidium vapor and realize controllable transmission of vector beams based on atomic dichroism. By utilizing the linearly polarized beam and vector beams as the pump and probe beams in a pump–probe configuration, a spatially-dependent dichroism can be obtained,which leads to spatially varied absorption of the probe beam. The controllable intensity distribution of the probe beam, as a two-petal pattern, can rotate with the variation of the pump beam's polarization states. We experimentally demonstrate the mechanism of dichroism with linear polarization light and provide an explanation based on the optical pumping effect.Alternatively, the varying trend of the probe beam's intensity is also interpreted by utilizing the Jones matrix. Our results are thus beneficial for providing potential applications in optical manipulation in atomic ensembles.

Risk of cardiac rupture after acute myocardial infarction is related to a risk of hemorrhage

Although cardiac rupture (CR) is a fatal mechanical complication of acute myocardial infarction (AMI), to date no predictive model for CR has been described. CR has common pathological characteristics with major bleeding. We aimed to investigate the relationship between the risk factors of major bleeding and CR. A total of 10 202 consecutive AMI patients were recruited, and mechanical complications occurred in 72 patients. AMI patients without CR were chosen as control group. Clinical characteristics including bleeding-related factors were compared between the groups. The incidences of free wall rupture (FWR), ventricular septal rupture (VSR), and papillary muscle rupture (PMR) were 0.39%, 0.21%, and 0.09%, respectively, and the hospital mortalities were 92.5%, 45.5%, and 10.0%, respectively. Female proportion and average age were significantly higher in the groups of FWR and VSR than in the control group (P<0.01); higher white blood cell count and lower hemoglobin were found in all CR groups (P<0.01). Compared to the control group, patients with CR were more likely to receive an administration of thrombolysis [26.39% vs. 13.19%, P<0.05], and were less likely to be treated with primary percutaneous coronary intervention (PCI) [41.67% vs. 81.60%, P<0.05]. The major bleeding scores (integer scores) of FWR, VSR, and PMR were (17.70±7.24), (21.91±8.33), and (18.60±7.88), respectively, and were significantly higher than that of the control group (11.72±7.71) (P<0.05). A regression analysis identified age, increased heart rate, anemia, higher white blood cell count, and thrombolysis as independent risk factors of CR, most of which were major bleeding-related factors. The patients with CR have a significantly higher risk of hemorrhage compared to the group without CR. Risk of CR after AMI is related to the risk of hemorrhage.

Predictive factors of cardiac rupture in patients with ST-elevation myocardial infarction

Cardiac rupture （CR） is a potentially fatal mechanical complication of ST-elevation myocardial infarction （STEMI）. We aimed to determine the incidence and risk factors of CR in Chinese STEMI patients. A total of 9798 consecutive STEMI patients from four centers in China were retrospectively analyzed, among which 178 patients had CR. STEMI patients without CR were chosen as a control group. Clinical characteristics were compared between STEMI patients with CR and those without CR. The incidence of CR in STEMI patients was 1.82%, and the 30-d mortality was up to 61.2%. CR patients were significantly older, more female, and associated with a longer time from onset of pain to hospital admission than their non-CR counterparts （P〈0.001）. More patients with anterior myocardial infarction （82.1%） were found in the CR group, and CR patients had significantly higher heart rates than the control group （（91±19） bpm vs. （71±16） bpm; P〈0.001）. In multiple-adjusted models, the independent risk factors of CR were advanced age, female gender, anaemia, increased heart rate, anterior myocardial infarction, increased white blood cell （WBC） count, delayed admission, and renal dysfunction. The level of hemoglobin remained a significant deter- minant factor of CR （OR （95% CI）： 0.82 （0.75-0.89）; P〈0.001） after adjusting for various potential confounding factors. Counts of WBC also remained a significant determinant of the CR （OR （95% CI）： 1.08 （1.04-1.12）; P〈0.001）. A number of variables were independently related to CR. This study indicated, for the first time, that both hemoglobin and WBC levels were independently correlated with occurrence of CR.

THE EFFECT OF SILICA MORPHOLOGY ON PROPERTIES OF PVA/SILICA NANO-COMPOSITES

Two kinds of poly（vinyl alcohol） （PVA）-silica composites were prepared with different methods. One composite was prepared by directly mixing PVA with 80 nm silica nano-particles which were made from tetraethoxysilane （TEOS）. The another was obtained by the mixing PVA and hydrolyzed TEOS in the presence of acid-catalyst. The properties of the two PVA/silica hybrids were characterized by means of scanning electron microscopy （SEM）, UV-Visible spectroscopy, solubility tests, limiting oxygen index （LOI） test, tensile test and dynamical mechanical analysis （DMA）, respectively. The results indicate that PVA-TEOS composites （PT for short） display more transparency than PVA-silica nano-particles hybrids （PS for short）. At the same time, The PT composites presented more excellent performance than PS in water resistance, fire resistance and mechanical properties. Moreover, the Tg of PT increased with increasing TEOS content, while that of PS decreased.