Studies on the Power Requirement of Mixing Impellers (IV) : Empirical Equations Applicable for a Wide Range

The present authors have already reported on the empirical equations for the power requirement of paddle agitators. In this report, equations for the three ranges of high, medium, and low viscosity were made and equations for the maximum power required under fully baffled conditions were also formed separately. Although the results are accurate, these equations are not always convenient because of the complexity in deciding which form to be used. On the basis of a reasonable assumption derived from the essential concept of power consumption, the authors derived an empirical equation which covers wide ranges of power data as follows : Nₚ=A/Rₑ + B(10³+1.2Rₑ⁰.⁶⁶/10³+3.2Rₑ⁰.⁶⁶)ᵖ(H/D)⁽⁰.³⁵⁺ᵇ/ᴰ⁾ (sinθ)¹.² (27) where A=14+(b/D){670(d/D-0.6)²+185} (19) B=10{1.3-4(b/D-0.5)²-1.14(d/D)} (22) p=1.1+4(b/D)-2.5(d/D-0.5)²-7(b/D)⁴ (23) The maximum power consumption of paddle agitators can also be calculated by Eq. (27) by substituting Re with the values of Rc and Rθ which can be obtained by the following equations : For the paddle having a blade angle of 90°, Rc=25/(b/D)(d/D-0.4)²+{b/D0.11(b/D)-0.0048} (28) For the paddle having an arbitrary angle of θ, Rθ=10⁴(1-sinθ)Rc (30) Fairly good agreements were obtained between those values calculated by the equations and those obtained by the experiments

Mass Spectrometric Study of the Negative Ion Formation of Nitroethylene at High Electron Energies

The formation of the molecular and the dimer negative ions of nitroethylene at high electron energies was studied. The intensity of the molecular negative ion showed a second order dependence on the pressure below 10⁻⁴ torr and a higher than second order dependence above 10⁻⁴ torr. The intensity of the dimer negative ion showed a second order dependence greater than that of the molecular negative ion. The intensity of the molecular negative ion was found to be dependent on the pressure of additional rare gases. This suggests that the collisional stabilization of excited ions is very important at high electron energies

Risk Factors for Nosocomial Infection in the Neonatal Intensive Care Unit by the Japanese Nosocomial Infection Surveillance (JANIS)

We evaluated the infection risks in the neonatal intensive care unit (NICU) using data of NICU infection surveillance data. The subjects were 871 NICU babies, consisting of 465 boys and 406 girls, who were cared for between June 2002 and January 2003 in 7 medical institutions that employed NICU infection surveillance. Infections were defined according to the National Nosocomial Infection Surveillance (NNIS) System. Of the 58 babies with nosocomial infections, 15 had methicillin-resistant Staphylococcus aureus (MRSA) infection. Multiple logistic regression analysis demonstrated that the odds ratio for nosocomial infections was significantly related to gender, birth weight and the insertion of a central venous catheter (CVC). When the birth weight group of more than 1, 500g was regarded as the reference, the odds ratio was 2.35 in the birth weight group of 1,000-1,499g and 8.82 in the birth weight group of less than 1,000g. The odds ratio of the CVC () for nosocomial infection was 2.27. However, other devices including artificial ventilation, umbilical artery catheter, umbilical venous catheter, and urinary catheter were not significant risk factors. The incidence of MRSA infection rapidly increased from 0.3% in the birth weight group of more than 1,500g to 2.1% in the birth weight group of 1,000-1,499g, and to 11.1% in the birth weight group of less than 1,000g. When the birth weight group of more than 1,500g was regarded as the reference, multiple logistic regression analysis demonstrated that the odds ratio was 7.25 in the birth weight group of 1,000-1,499g and 42.88 in the birth weight group of less than 1,000g. These odds ratios were significantly higher than that in the reference group. However, the application of devices did not cause any significant differences in the odds ratio for MRSA infection.</p

Benign giant mediastinal schwannoma presenting as cardiac tamponade in a woman: a case report

<p>Abstract</p> <p>Introduction</p> <p>Mediastinal schwannomas are typically benign and asymptomatic, and generally present no immediate risks. We encountered a rare case of a giant benign posterior mediastinal schwannoma, complicated by life-threatening cardiac tamponade.</p> <p>Case presentation</p> <p>We report the case of a 72-year-old Japanese woman, who presented with cardiogenic shock. Computed tomography of the chest revealed a posterior mediastinal mass 150 cm in diameter, with pericardial effusion. The cardiac tamponade was treated with prompt pericardial fluid drainage. A biopsy was taken from the mass, and after histological examination, it was diagnosed as a benign schwannoma, a well-encapsulated non-infiltrating tumor, originating from the intrathoracic vagus nerve. It was successfully excised, restoring normal cardiac function.</p> <p>Conclusion</p> <p>Our case suggests that giant mediastinal schwannomas, although generally benign and asymptomatic, should be excised upon discovery to prevent the development of life-threatening cardiopulmonary complications.</p

Neurogenesis in the dentate gyrus of the rat hippocampus enhanced by tickling stimulation with positive emotion

Hippocampal neurogenesis is influenced by many factors. In this study, we examined the effect of tactile stimulation (tickling), which induced positive emotion, on neurogenesis in the dentate gyrus (DG) of the hippocampus. Four week-old rats were tickled for 5 min/day on 5 consecutive days and received 5-bromo-2′-deoxyuridine (BrdU) administration for 4 days from the second tickling day. Then they were allowed to survive for 18 h or 3 weeks after the end of BrdU treatment. Neurogenesis in the DG was compared between the tickled and untickled rats by using immunohistochemistry with anti-BrdU antibody. The result showed that the number of BrdU- and NeuN (neural cell marker)-double positive neurons on 18 h as well as 3 weeks of the survival periods was significantly increased in the tickled group as compared with the untickled group. The expression of mRNA of brain-derived neurotrophic factor (BDNF) in the hippocampus of the tickled rats was not altered when compared with the control rats. In conclusion, tickling stimulation which induces positive emotion may affect the generation and survival of new neurons of the DG through the BDNF-independent pathway

Investigating nuclear shell structure in the vicinity of 78Ni: Low-lying excited states in the neutron-rich isotopes 80,82Zn

L

Aging and circadian rhythms

In many animal species including humans, numerous processes exhibit 24-hour (h) rhythms. The circadian clock regulates daily rhythms of behavior and physiology such as the sleep-wake cycle (activity/rest), autonomic nervous function, and neuroendocrine function. The mammalian master clock located in the suprachiasmatic nuclei (SCN) of the hypothalamus incorporates environmental information and orchestrates peripheral clocks in other tissues and organs. Various characteristics of daily rhythms undergo age-dependent changes with respect to amplitude, entrained phase, free-running period (τ), and reentrainability. The mechanisms underlying aging of the circadian clock have not been fully understood. This review discusses current findings on age-related changes in daily rhythms of behavior and physiology

Clinical and MRI features of Japanese MS patients with NMO-IgG

ABSTRACT Background: NMO-IgG is a disease-specific serum marker autoantibody of neuromyelitis optica (NMO) and may distinguish NMO from multiple sclerosis (MS). NMO-IgG has also been frequently detected in Japanese patients with the optic-spinal form of MS (OSMS) suggesting that NMO and OSMS may be the same entity

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)