Tailoring optical nonlinearities via the Purcell effect.

We predict that the effective nonlinear optical susceptibility can be tailored using the Purcell effect. While this is a general physical principle that applies to a wide variety of nonlinearities, we specifically investigate the Kerr nonlinearity. We show theoretically that using the Purcell effect for frequencies close to an atomic resonance can substantially influence the resultant Kerr nonlinearity for light of all (even highly detuned) frequencies.

Tracing the effects of the Little Ice Age in the tropical lowlands of eastern Mesoamerica.

The causes of late-Holocene centennial to millennial scale climatic variability and the impact that such variability had on tropical ecosystems are still poorly understood. Here, we present a high-resolution, multiproxy record from lowland eastern Mesoamerica, studied to reconstruct climate and vegetation history during the last 2,000 years, in particular to evaluate the response of tropical vegetation to the cooling event of the Little Ice Age (LIA). Our data provide evidence that the densest tropical forest cover and the deepest lake of the last two millennia were coeval with the LIA, with two deep lake phases that follow the Spörer and Maunder minima in solar activity.

Effects of delayed oxygenation assessment on time to antibiotic delivery and mortality in patients with severe community-acquired pneumonia.

Background: Practice guidelines suggest processes of care such as timely oxygenation assessment and antibiotic therapy as quality indicators for the management of community-acquired pneumonia. The objective of this study was to determine whether postponed oxygenation assessment (either by pulse oximetry monitoring or arterial blood gas analysis) delays initiation of antibiotic therapy and adversely affects intensive care unit survival in patients with severe community-acquired pneumonia.

Methods: Secondary analysis from a prospective, observational, multicenter study including 529 patients with community-acquired pneumonia admitted to the intensive care unit in 33 hospitals.

Rice straw pulp obtained by using various methods.

Rice straw was used as an alternative raw material to obtain cellulosics pulps. Pulping was done by using classics reagents as soda (with anthraquinone and parabenzoquinone as aditives), potassium hydroxide and Kraft process. The holocellulose, alpha-cellulose and lignin contents of rice straw (viz.

Effect of the pineal hormone melatonin on teleost fish phagocyte innate immune responses after in vitro treatment.

Although neuroendocrine-immune system interaction has been shown in teleost fish, no study has evaluated the role of melatonin (Mel) on fish immune response even considering that it is affected by the photoperiod. Gilthead seabream (Sparus aurata L.) and sea bass (Dicentrarchus labrax L.

Laparoscopic retroperitoneal lymph node dissection in the management of testis cancer.

Background: The surgical approach to management of testis cancer has been traditionally through an open incision, but in the last decade, several centers have reported their experience with laparoscopic retroperitoneal lymph node dissection (LRPLND).

Methods: We reviewed the English literature, summarized the outcomes, and included our initial experience with the LRPLND procedure.

Results: Improvements in operative time, complications, and morbidity have occurred as surgical experience has increased.

Pure laparoscopic and robotic-assisted laparoscopic radical prostatectomy in the management of prostate cancer.

Background: Until recently, open radical prostatectomy was the only approach for the surgical management of prostate cancer. Laparoscopy is now increasingly used as an alternative approach. The procedure can be performed directly or with robot assistance.

Laparoscopic management of kidney cancer: updated review.

Background: Laparoscopy has emerged as the preferred option for the surgical management of kidney cancer. Although many reports have been published regarding the operative outcome of renal cell carcinoma (RCC) and upper-tract transitional cell carcinoma (TCCA) treated laparoscopically, few review the oncologic outcome of these pathologies treated with laparoscopic techniques.

Methods: We review the literature regarding the laparoscopic approaches, the complications related to laparoscopic surgery, and the long-term oncologic results of laparoscopic radical nephrectomy, partial nephrectomy, and nephroureterectomy.

Management of ventilator-associated pneumonia in a multidisciplinary intensive care unit: does trauma make a difference?

Objective: Antibiotic exposure and timing of pneumonia onset influence ventilator-associated pneumonia (VAP) isolates. The first goal of this investigation was to evaluate whether trauma also influences prevalence of microorganisms.

Design: A retrospective, single-center, observational cohort study.

Chi((2)) and Chi((3)) harmonic generation at a critical power in inhomogeneous doubly resonant cavities.

We derive general conditions for 100% frequency conversion in any doubly resonant nonlinear cavity, for both second- and third-harmonic generation via Chi?((2))and Chi((3)) nonlinearities. We find that conversion efficiency is optimized for a certain "critical" power depending on the cavity parameters, and assuming reasonable parameters we predict 100% conversion using milliwatts of power or less. These results follow from a semi-analytical coupled-mode theory framework which is generalized from previous work to include both Chi((2))and Chi((3))?media as well as inhomogeneous (fully vectorial) cavities, analyzed in the high-efficiency limit where down-conversion processes lead to a maximum efficiency at the critical power, and which is verified by direct finite-difference time-domain (FDTD) simulations of the nonlinear Maxwell equations.

Adenosine arrests apoptosis in lymphocytes but not in phagocytes from primary leucocyte cultures of the teleost fish, Sparus aurata L.

Adenosine (A) and its derivatives have important biological functions, including the inhibition of immune responses and apoptosis induction. The aim of this work was to investigate whether A and N(6)-cyclohexyladenosine (CHA) regulate apoptosis in leukocyte cultures from the teleost, gilthead seabream (Sparus aurata L.) by flow cytometry using a double fluorescence staining method.

Use of high-boiling point organic solvents for pulping oil palm empty fruit bunches.

Oil palm empty fruit bunches were used as an alternative raw material to obtain cellulosic pulp. Pulping was done by using high-boiling point organic solvents of decreased polluting power relative to classical (Kraft, sulphite) solvents but affording operation at similar pressure levels. The holocellulose, alpha-cellulose and lignin contents of oil palm empty fruit bunches (viz.

Neural fuzzy model applied to ethylene-glycol pulping of non-wood raw materials.

We studied the influence of the operational variables (viz. ethylene-glycol concentrations of 50-70%, temperatures of 155-185 degrees C, times of 30-90 min and numbers of PFI beating revolutions of 500-1500) on pulp yield and various paper properties (breaking length, stretch, burst index, tear index and brightness) obtained in the ethylene-glycol pulping of vine shoots, cotton stalks, leucaena (Leucaena leucocephala) and tagasaste (Chamaecytisus proliferus). The fuzzy neural network models used reproduced the experimental results with errors less than 15% and smaller than those provided by second-order polynomial models in all cases.

Combination antibiotic therapy improves survival in patients with community-acquired pneumonia and shock.

Objective: To assess whether combination antibiotic therapy improves outcome of severe community-acquired pneumonia in the subset of patients with shock.

Design: Secondary analysis of a prospective observational, cohort study.

Setting: Thirty-three intensive care units (ICUs) in Spain.

Laparoscopic extraperitoneal radical prostatectomy in complex surgical cases.

Purpose: Patients with a high body mass index, previous pelvic surgery or large prostate size are not considered ideal candidates for radical prostatectomy. We assessed the impact of body mass index, previous pelvic surgery and prostate weight on perioperative and pathological outcomes in patients treated exclusively with laparoscopic extraperitoneal radical prostatectomy.

Materials And Methods: From January 2004 to May 2005, 300 patients underwent laparoscopic extraperitoneal radical prostatectomy.

Composition of an avian guild in spatially structured habitats supports a competition-colonization trade-off.

Assuming better colonization abilities of inferior competitors, the competition-colonization trade-off (CCTO) is one of the hypotheses that explains spatial variation of species composition in fragmented habitats. Whereas this mechanism may structure some plant and insect communities, ecologists have failed to document its operation in other natural systems, and its generality has been questioned. We combined fieldwork and published data to study the composition of a guild of passerines (Parus cristatus, Parus montanus, Parus ater and Regulus regulus) inhabiting 10 landscapes that differed in the amount of forest habitat.

Oral care practices in intensive care units: a survey of 59 European ICUs.

Objective: To explore the type and frequency of oral care practices in European ICUs and the attitudes, beliefs, and knowledge of health care workers.

Design: An anonymous questionnaire was distributed to representatives of European ICUs. Results were obtained from 59 ICUs (one questionnaire per ICU) in seven countries 91% of respondents were registered nurses.

Pulping of holm oak wood. Influence of the operating conditions.

This paper reports on the influence of independent variables in the pulping of holm oak wood (Quercus ilex L.) [viz. temperature (135-195 degrees C), cooking time (30-90min) and soda concentration (10-20%)] on the yield, holocellulose content, alpha-cellulose content, brightness and viscosity of the resulting pulp.

Lack of BK virus DNA sequences in most transitional-cell carcinomas of the bladder.

BK virus (BKV), a common human polyomavirus infection latent in the kidneys, can reactivate with immunosuppression to cause renal disease. Some have suggested that BKV may contribute to the development of bladder cancer, and BKV sequences have been reported from bladder tumors. To further examine the role of BKV in human bladder cancer, a series of bladder tumors was investigated for BKV genomic sequences.

A quantum mechanics/molecular mechanics study of the reaction mechanism of the hepatitis C virus NS3 protease with the NS5A/5B substrate.

Combined quantum mechanics and molecular mechanics (QM/MM) calculations were carried out to characterize the reaction mechanism of the NS3 protease with its preferred substrate (NS5A/5B). The main purpose of this study was to locate the barrier states and intermediates along the distinguished coordinate path (DCP) involved in this process. These structures, and in particular the one corresponding to the first barrier state and intermediate (B1 and I1), could be a starting point for the synthesis of inhibitors of this protease, which could be used to treat hepatitis C.

Risk factors for ventilator-associated pneumonia by Pseudomonas aeruginosa in presence of recent antibiotic exposure.

Background: To facilitate the decision-making process for therapy and prevention of ventilator-associated pneumonia (VAP) in patients undergoing recent antibiotic exposure, this study investigated whether the development of VAP episodes caused by Pseudomonas aeruginosa or other pathogens are related to different risk factors, thereby distinguishing two risk population for this serious complication.

Methods: A 5-year retrospective case-control observational study was conducted. Cases of VAP caused by P.

Improving accuracy by subpixel smoothing in the finite-difference time domain.

Finite-difference time-domain (FDTD) methods suffer from reduced accuracy when modeling discontinuous dielectric materials, due to the inhererent discretization (pixelization). We show that accuracy can be significantly improved by using a subpixel smoothing of the dielectric function, but only if the smoothing scheme is properly designed. We develop such a scheme based on a simple criterion taken from perturbation theory and compare it with other published FDTD smoothing methods.

Risk factors for asthma and allergy associated with urban migration: background and methodology of a cross-sectional study in Afro-Ecuadorian school children in Northeastern Ecuador (Esmeraldas-SCAALA Study).

Background: Asthma and allergic diseases are becoming increasingly frequent in children in urban centres of Latin America although the prevalence of allergic disease is still low in rural areas. Understanding better why the prevalence of asthma is greater in urban migrant populations and the role of risk factors such as life style and environmental exposures, may be key to understand what is behind this trend.

Methods/design: The Esmeraldas-SCAALA (Social Changes, Asthma and Allergy in Latin America) study consists of cross-sectional and nested case-control studies of school children in rural and urban areas of Esmeraldas Province in Ecuador.