Metamaterial Polarization Converter Analysis: Limits of Performance

In this paper we analyze the theoretical limits of a metamaterial converter that allows for linear-to- elliptical polarization transformation with any desired ellipticity and ellipse orientation. We employ the transmission line approach providing a needed level of the design generalization. Our analysis reveals that the maximal conversion efficiency for transmission through a single metamaterial layer is 50%, while the realistic re ection configuration can give the conversion efficiency up to 90%. We show that a double layer transmission converter and a single layer with a ground plane can have 100% polarization conversion efficiency. We tested our conclusions numerically reaching the designated limits of efficiency using a simple metamaterial design. Our general analysis provides useful guidelines for the metamaterial polarization converter design for virtually any frequency range of the electromagnetic waves.Comment: 10 pages, 11 figures, 2 table

Cluster of SARS among Medical Students Exposed to Single Patient, Hong Kong

We studied transmission patterns of severe acute respiratory syndrome (SARS) among medical students exposed exclusively to the first SARS patient in the Prince of Wales Hospital in Hong Kong, before his illness was recognized. We conducted a retrospective cohort study of 66 medical students who visited the index patient’s ward, including 16 students with SARS and 50 healthy students. The risk of contracting SARS was sevenfold greater among students who definitely visited the index case’s cubicle than in those who did not (10/27 [41%] versus 1/20 [5%], relative risk [RR] 7.4; 95% confidence interval [CI] 1.0 to 53.3). Illness rates increased directly with proximity of exposure to the index case. However, four of eight students who were in the same cubicle, but were not within 1 m of the index case-patient, contracted SARS. Proximity to the index case-patient was associated with transmission, which is consistent with droplet spread. Transmission through fomites or small aerosols cannot be ruled out

Global, regional, and national age-sex-specific mortality and life expectancy, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND: Assessments of age-specific mortality and life expectancy have been done by the UN Population Division, Department of Economics and Social Affairs (UNPOP), the United States Census Bureau, WHO, and as part of previous iterations of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD). Previous iterations of the GBD used population estimates from UNPOP, which were not derived in a way that was internally consistent with the estimates of the numbers of deaths in the GBD. The present iteration of the GBD, GBD 2017, improves on previous assessments and provides timely estimates of the mortality experience of populations globally. METHODS: The GBD uses all available data to produce estimates of mortality rates between 1950 and 2017 for 23 age groups, both sexes, and 918 locations, including 195 countries and territories and subnational locations for 16 countries. Data used include vital registration systems, sample registration systems, household surveys (complete birth histories, summary birth histories, sibling histories), censuses (summary birth histories, household deaths), and Demographic Surveillance Sites. In total, this analysis used 8259 data sources. Estimates of the probability of death between birth and the age of 5 years and between ages 15 and 60 years are generated and then input into a model life table system to produce complete life tables for all locations and years. Fatal discontinuities and mortality due to HIV/AIDS are analysed separately and then incorporated into the estimation. We analyse the relationship between age-specific mortality and development status using the Socio-demographic Index, a composite measure based on fertility under the age of 25 years, education, and income. There are four main methodological improvements in GBD 2017 compared with GBD 2016: 622 additional data sources have been incorporated; new estimates of population, generated by the GBD study, are used; statistical methods used in different components of the analysis have been further standardised and improved; and the analysis has been extended backwards in time by two decades to start in 1950. FINDINGS: Globally, 18·7% (95% uncertainty interval 18·4–19·0) of deaths were registered in 1950 and that proportion has been steadily increasing since, with 58·8% (58·2–59·3) of all deaths being registered in 2015. At the global level, between 1950 and 2017, life expectancy increased from 48·1 years (46·5–49·6) to 70·5 years (70·1–70·8) for men and from 52·9 years (51·7–54·0) to 75·6 years (75·3–75·9) for women. Despite this overall progress, there remains substantial variation in life expectancy at birth in 2017, which ranges from 49·1 years (46·5–51·7) for men in the Central African Republic to 87·6 years (86·9–88·1) among women in Singapore. The greatest progress across age groups was for children younger than 5 years; under-5 mortality dropped from 216·0 deaths (196·3–238·1) per 1000 livebirths in 1950 to 38·9 deaths (35·6–42·83) per 1000 livebirths in 2017, with huge reductions across countries. Nevertheless, there were still 5·4 million (5·2–5·6) deaths among children younger than 5 years in the world in 2017. Progress has been less pronounced and more variable for adults, especially for adult males, who had stagnant or increasing mortality rates in several countries. The gap between male and female life expectancy between 1950 and 2017, while relatively stable at the global level, shows distinctive patterns across super-regions and has consistently been the largest in central Europe, eastern Europe, and central Asia, and smallest in south Asia. Performance was also variable across countries and time in observed mortality rates compared with those expected on the basis of development. INTERPRETATION: This analysis of age-sex-specific mortality shows that there are remarkably complex patterns in population mortality across countries. The findings of this study highlight global successes, such as the large decline in under-5 mortality, which reflects significant local, national, and global commitment and investment over several decades. However, they also bring attention to mortality patterns that are a cause for concern, particularly among adult men and, to a lesser extent, women, whose mortality rates have stagnated in many countries over the time period of this study, and in some cases are increasing

Cyber incivility at the workplace: What has supervisor's sex got to do with it?

PACIS 2006 - 10th Pacific Asia Conference on Information Systems: ICT and Innovation Economy1247-125

Etiology and cytokine expression in patients requiring mechanical ventilation due to severe community-acquired pneumonia

Background: The relationship between bacterial etiology and serum cytokine levels in patients with severe community-acquired pneumonia (CAP) without response to initial empiric treatment remains unclear. This study investigated the bacterial etiology, outcomes, and bronchoalveolar and systemic cytokines (interleukin [IL]-1 beta, IL-8, IL-10) in these patients. Methods: This hospital-based study enrolled 47 consecutive patients without response to initial empiric treatment and requiring mechanical ventilation due to severe CAP between July 1, 2000 and October 31, 2001, in a respiratory intensive care unit of a 1200-bed teaching hospital in central Taiwan. Bronchoalveolar lavage (BAL) was performed within 3 days after hospitalization. BAL fluid was processed for quantitative bacterial cultures. Blood samples were taken just before BAL, and the levels of both BAL and serum cytokines were measured. Results: The most common pathogens isolated were Pseudomonas aeruginosa (22.5%) and Klebsiella pneumoniae (25%). Patients with a K. pneumoniae isolate (n = 10) had significantly higher levels of IL-1 beta in BAL fluid and significantly higher levels of IL-10 in serum and BAL fluid than patients with other etiologies. Non-survivors had higher levels of serum IL-8 (p = 0.001), serum IL-10 (p < 0.001) and BAL IL-10 (p = 0.039) than survivors. Marked increases in local and systemic cytokine expression (IL-8 and IL-10) were noted in rapidly fatal cases. Conclusion: P. aeruginosa and K. pneumoniae are the most common causes of CAP requiring mechanical ventilation in Taiwan. Cytokine patterns in the BAL fluid and serum of patients with severe CAP due to K. pneumoniae showed significant elevations compared to other pathogens. Bronchoalveolar and systemic cytokine levels (especially IL-10) predicted mortality. These findings suggest the need for a clinical trial to determine how immunomodulating therapy might affect cytokine profiles and clinical outcome

Key Process Indicators of Mortality in the Implementation of Protocol-driven Therapy for Severe Sepsis

Background/Purpose: Severe sepsis and septic shock are life-threatening disorders. Integrating treatments into a bundle strategy has been proposed to facilitate timely resuscitation, but is difficult to implement. We implemented protocol-driven therapy for severe sepsis, and analyzed retrospectively the key pro cess indicators of mortality in managing sepsis. Methods: Continuous quality improvement was begun to implement a tailored protocol-driven therapy for sepsis in a 24-bed respiratory intensive care unit (RICU) of Taichung Veterans General Hospital from January 2007 to February 2008. Patients, who were admitted to the RICU directly, or wit in 24 ours, were enrolled if they met the criteria for severe sepsis and septic shock. Disease severity [Acute Physiology and Chronic Health Evaluation (APACHE) II and lactate level], causes of sepsis, comorbidity and site of sepsis onset were recorded. Process-of-care indicators included resuscitation time (Tr-s), RICU bed availability (Ti-s) and the ratio of completing the elements of the protocol at 1, 2, 4 and 6 hours. The structure and process-of-care indicators related to mortality at 7 days after RICU admission and at RICU discharge were identified retrospectively. Results: Eighty-six patients (mean age, 71 +/- 14 years; 72 men, 14 women; APACHE II, 25.0 +/- 7.0) were enrolled. APACHE II scores and lactate levels were higher for mortality than survival at 7 days after RICU admission (p<0.01). For the process-of-care indicators, Ti-s (562.2 +/- 483.3 vs. 1017.3 +/- 557.8 minutes, p=0.03) and Tr-s (60.7 +/- 207.8 vs. 248.5 +/- 453.1 minutes, p=0.07) were shorter for survival than mortality at 7 days after RICU admission. The logistic regression study showed that Tr-s was an important indicator. The ratio of completing the elements of protocols at 1, 2, 4 and 6 hours ranged from 70% to 90% and was not related to mortality. Conclusion: Protocol-driven therapy for sepsis was put into clinical practice. Early resuscitation and ICU bed availability were key process indicators in managing sepsis, to reduce mortality. [J Formos Med Assoc 2009; 108(10):778-787

Bleb related infections: Clinical characteristics,risk factors,and outcomes in an Asian population

10.2147/OPTH.S118809Clinical Ophthalmology102303-230