Fine-structure transitions of Si and S induced by collisions with atomic hydrogen

Using a quantum-mechanical close-coupling method, we calculate cross sections for fine structure excitation and relaxation of Si and S atoms in collisions with atomic hydrogen. Rate coefficients are calculated over a range of temperatures for astrophysical applications. We determine the temperature-dependent critical densities for the relaxation of Si and S in collisions with H and compare these to the critical densities for collisions with electrons. The present calculation should be useful in modeling environments exhibiting the [S i] 25 {\mu}m and [S i] 57 {\mu}m far-infrared emission lines or where cooling of S and Si by collisions with H are of interest.Comment: Accepted for publication in MNRA

3,6-Dihydr­oxy-2′-[(2-hydr­oxy-1-naphth­yl)methyl­eneamino]xanthene-9-spiro-1′-isoindolin-3′-one acetonitrile solvate

The title compound, C31H20N2O5·C2H3N, was synthesized by the reaction of fluorescein hydrazide and excess 2-hydr­oxy-1-naphthaldehyde in acetonitrile. The spirolactam ring is planar and is nearly at right angles to the two benzene rings of the xanthene system. The dihedral angle between the two benzene rings of the xanthene system is 9.92 (4)°. In the crystal structure, the mol­ecules are linked into extended two-dimensional networks by inter­molecular hydrogen bonding. Acetonitrile mol­ecules are located in the voids between the two-dimensional networks

Predicting the Floc Characteristics and Settling Velocity of Flocs under Variable Dosage of Polyacrylamide

In this study, floc characteristics such as fractal dimension and settling velocity were investigated through a flocculantion process with a polyacrylamide (PAM) flocculant over a range of suspended particle concentrations, suspension type and flocculant dosage. The floc’s structure and morphology were characterized by optical microscopy and scanning electron microscopy (SEM) methods. Floc settling velocity was measured in a settling column in a laboratory. The results showed that, the surface fractal dimension ranged from 1.044 to 1.415, which quantitatively confirmed the round and layered structure of flocs observed in SEM analyses. The PAM flocculant was proved to be more effective in flocculantion process, increasing the settling velocity. Therefore, an appropriate PAM dosage is an excellent candidate as efficient flocculant. A possible flocculantion mechanism for PAM was further analyzed. For alkaline or neutral environments, adsorption and bridging effects are dominant while charge neutralization is favored in acidic conditions.In this study, floc characteristics such as fractal dimension and settling velocity were investigated through a flocculantion process with a polyacrylamide (PAM) flocculant over a range of suspended particle concentrations, suspension type and flocculant dosage. The floc’s structure and morphology were characterized by optical microscopy and scanning electron microscopy (SEM) methods. Floc settling velocity was measured in a settling column in a laboratory. The results showed that, the surface fractal dimension ranged from 1.044 to 1.415, which quantitatively confirmed the round and layered structure of flocs observed in SEM analyses. The PAM flocculant was proved to be more effective in flocculantion process, increasing the settling velocity. Therefore, an appropriate PAM dosage is an excellent candidate as efficient flocculant. A possible flocculantion mechanism for PAM was further analyzed. For alkaline or neutral environments, adsorption and bridging effects are dominant while charge neutralization is favored in acidic conditions

The effect of drainage tube on bleeding and prognosis after total knee arthroplasty: a prospective cohort study

BACKGROUND: To evaluate the effect of drainage tube on prognosis after total knee arthroplasty (TKA) and explore an effective treatment with favorable prognosis. METHODS: In a prospective study, 18 patients with TKA for the first time were included and randomly divided into three groups, group A (no placement of drainage tube), group B (negative pressure drainage), and group C (4 h clamping drainage). Intraoperative and postoperative blood loss, operation time, and the drainage volume were recorded and analyzed. Arthrocele, ecchymosis, and range of motion (ROM) were examined postoperatively. The degree of pain was scored by Visual Analog Scale (VAS) after 6, 12, and 24 h of operation. The complications were examined and HSS (hospital for special surgery) knee score was taken during the follow-up period. RESULTS: There was no significant difference in operation time, total blood loss, intraoperative blood loss, and VAS score among three groups. Meanwhile, the hidden blood loss in group B was significantly decreased compared with group A (P = 0.0015). The postoperative drainage volume of group B was significantly increased compared with group C (P = 0.0002). No drainage increased the rate of arthrocele and ecchymosis. Compared with group A, ROM after 3 days of operation in groups B and C was significantly increased (P = 0.0357, P = 0.0372, respectively). During follow-up study, no deep infection or deep venous thrombosis was found. CONCLUSION: After TKA, early clamping of the drainage tube reduced the bleeding loss without adverse effect on prognosis, which might be useful for clinical application in future

African Journal of Biotechnology

In this study, we aimed to evaluate the global scientific production of Taxus (yew) research, study the characteristics of Taxus research activities, and identify patterns, tendencies, and regularities of Taxusrelated articles. Data were based on the online version of Science Citation Index Expanded (SCIExpanded), from the Web of Science database. Articles referring to Taxus were assessed by the trend of publication output during 1991 to 2010. Globally, 2,916 papers were published during the 20-year study period. The most productive countries, institutions, Web of Science subject categories, and journals, as well as the most cited articles, were identified. The mainstream research on Taxus was in the plant sciences, biochemistry and molecular biology, cardiac and cardiovascular systems, biotechnology and applied microbiology. The G7 industrial countries, as well as China and India held the majority of total world production. Research on the various economically important Taxus species remained the hotspot during the 20-year study period, whereas that on the related topic "paclitaxel eluting stents" increased dramatically since 2002. With synthetic analysis of word in article title, author keyword, abstract, and key words Plus, it can be concluded that application of compounds derived from Taxus in clinical cardiology, pharmacology and oncology, and research related to Taxus chemistry, metabolism, cytology and microbiology is the ongoing Taxus-related research in the 21st century. Gaps are present in knowledge about the genomics, epigenomics, transcriptomics, proteomics, metabolomics and bioinformatics of Taxus and their endophytic fungi