Filtration properties of nanofiber/microfiber mixed filter and prediction of its performance

There is an increasing demand of air filters with a high collection performance, i.e., high collection efficiency and low pressure drop, for the application to indoor air cleaning. Air filters consisting of nanofibers have attracted great interests since they may have a low pressure drop because of slip flow effect and high collection efficiency due to interception. Although various nanofiber filters are available on the market, their collection performance is not as high as expected by the conventional filtration theory because non-uniform packing of fibers plays a significant role. In the present work, the collection performance of nanofiber (780 nm) and microfiber (11.2 µm) mixed filters with various mixing fractions was studied in order to maximize the quality factor of filter, qF, as a function of mixing fraction of nanofibers. The collection performance of mixed fiber filters was predicted by using theoretical equations reported by Bao et al. (1998) for bimodal distribution of fibers. As a result, it was found that the mixed fiber filters had a uniform fiber packing compared to laminated filters and that the collection efficiency was well predicted by introducing the inhomogeneity factor calculated for the filter consisting of two distinct fiber sizes. Furthermore, we found that the mixed fiber filter with the nanofiber mixing fraction of 5% in mass had the highest quality factor. © Taiwan Association for Aerosol Research

Utility of Saline-Induced Resting Full-Cycle Ratio Compared with Resting Full-Cycle Ratio and Fractional Flow Reserve

Background. The saline-induced distal coronary pressure/aortic pressure ratio predicted fractional flow reserve (FFR). The resting full-cycle ratio (RFR) represents the maximal relative pressure difference in a cardiac cycle. Therefore, the present study aimed to compare the results of saline-induced RFR (sRFR) with FFR. Methods. Seventy consecutive lesions with only moderate stenosis were included. The FFR, RFR, and sRFR values were compared. The sRFR was assessed using an intracoronary bolus infusion of saline (2  mL/s) for five heartbeats. The FFR was obtained after an intravenous injection of papaverine. Results. Overall, the FFR, sRFR, and RFR values were 0.78 ± 0.12, 0.79 ± 0.13, and 0.83 ± 0.14, respectively. With regard to anatomical morphology were 40, 18, and 12 cases of focal, diffuse, and tandem lesion. There was a significant correlation between the sRFR and FFR (R = 0.96, p<0.01). There were also significant correlations between the sRFR and FFR in the left coronary and right coronary artery (R = 0.95, p<0.01 and R = 0.98, p<0.01). Furthermore, significant correlations between sRFR and FFR were observed in not only focal but also in nonfocal lesion including tandem and diffuse lesions (R = 0.93, p<0.01 and R = 0.97, p<0.01). A close agreement on FFR and sRFR was shown using the Bland–Altman analysis (95% CI of agreement: −0.08–0.07). In the receiver operating characteristic curve analysis, the cutoff value of sRFR to predict an FFR of 0.80 was 0.81 (area under curve, 0.97; sensitivity 90.6%; and specificity 98.2%). Conclusion. The sRFR can accurately and safely predict the FFR and might be effective for diagnosing ischemia

The response of NT-proBNP to intensified medication in advanced chronic heart failure

Background: The clinical significance of excessively high serum NT-proBNP is poorly understood in chronic heart failure (HF). Methods: One-hundred eighteen patients with advanced chronic HF (NYHA functional class III or IV) were admitted; of these patients, 42.4% exhibited NT-proBNP levels >10,000 pg/ml. The patients were divided into three groups as follows: ≥400 and <10,000 pg/ml, group I (n = 68); ≥10,000 and <20,000 pg/ml, group II (n = 28); and ≥20,000 pg/ml, group III (n = 22). The determinants of elevated NT-proBNP levels and responsiveness to HF medications were compared among these groups. A subgroup of HF patients with normal serum creatinine was analyzed separately. Results: Overall, cardiac, renal and laboratory parameters (serum creatinine, potassium and uric acid, positively; and eGFR and hemoglobin, negatively) correlated with serum NT-proBNP levels. In patients with normal serum creatinine, left ventricular ejection fraction, serum potassium and hemoglobin correlated with serum NT-proBNP levels. In-hospital mortality was higher in patients with the highest NT-proBNP levels. After successful HF treatment, the patients in each group lost body weight and improved to NYHA class I or II, and NT-proBNP levels were halved, irrespective of their baseline levels. Excessively high NT-proBNP levels were related to cardiac, renal and laboratory abnormalities; therefore, the role and underlying mechanism of high NT-proBNP levels must be studied further. Conclusion: Excessively high NT-proBNP levels in HF patients correlated with cardiac, renal and laboratory parameters. After successful HF treatment, NT-proBNP levels were halved, irrespective of their baseline levels. The precise role and underlying mechanism of NT-proBNP warrant further study

A Case of Undifferentiated Sarcoma in the Superior Vena Cava and Bilateral Cervical Veins

BACKGROUND Intimal sarcoma (IS) is a malignant mesenchymal tumor with predominantly intraluminal growth in large vessels and the heart. Due to the rarity of cases it often poses diagnostic problems in clinical and pathological settings. Although the classification of IS is still controversial, undifferentiated type of IS has recently been found to show immunohistochemical positivity with MDM2, CDK4, or PDGFRA and amplification of MDM2/CDK4 and PDGFRA. CASE REPORT The patient was a 76 years-old Japanese man who presented with superior vena cava (SVC) syndrome. CT identified a tumor or thrombi in the SVC, bilateral brachiocephalic, and jugular veins. The histology of the biopsy specimen revealed an undifferentiated tumor without immunohistochemical positivity for all antibodies available except vimentin and smooth muscle actin. He was treated conservatively and died of respiratory failure 2 months after presentation. At autopsy, the large veins were filled by a sausage-like tumor and the cut sections revealed hemorrhagic and necrotic tumor. The tumor cells were negative with MDM2, CDK4, and PDGFRA by immunohistochemistry. Amplification of MDM2 and PDGFRA was not identified by fluorescence in-situ hybridization. CONCLUSIONS We concluded that the case was an undifferentiated sarcoma (IS without any specific phenotype) arising in the SVC, bilateral brachiocephalic, and jugular veins. We propose a way of subtyping sarcomas with predominantly intraluminal growth in large vessels and the heart based on immunohistochemistry and amplification of MDM2 and PDGFRA. However, proper subtyping of these sarcomas requires further study.status: publishe

Cosensitization Properties of Glutathione-Protected Au25 Cluster on Ruthenium Dye-Sensitized TiO2 Photoelectrode

Cosensitization by glutathione-protected Au25 clusters on Ru complex, N719-sensitized TiO2 photoelectrodes is demonstrated. Glutathione-protected Au25 clusters showed no significant changes in properties after adsorption onto TiO2 particles, as confirmed by optical absorption spectroscopy, transmission electron microscopy, and laser desorption/ionization mass spectrometry. Adsorption property of the glutathione-protected Au25 clusters depends on the pH, which affects the incident photon-to-current conversion efficiency (IPCE) of the TiO2 photoelectrode containing Au25 clusters. When pH < 5, the IPCE increases with pH. Conversely, the IPCE decreases with pH when pH > 7. The IPCE of a TiO2 photoelectrode sensitized by both glutathione-protected Au25 clusters and N719 was increased compared with photoelectrodes containing either glutathione-protected Au25 clusters or N719, which suggests that glutathione-protected Au25 clusters act as a coadsorbent for N719 on TiO2 photoelectrodes. This is also supported by the results that the IPCE of N719-sensitized TiO2 photoelectrodes increased upon addition of glutathione. Furthermore, cosensitization by glutathione-protected Au25 clusters on N719-sensitized TiO2 photoelectrodes allows that wavelength of photoelectric conversion was extended to the near infrared (NIR) region. These results suggest that glutathione-protected Au25 clusters act not only as a coadsorbent to increase IPCE but also as an NIR-active sensitizer