Ring Cavity Erbium-Doped Fiber for Refractive Index Measurements.

In this study, an interrogation system based on an erbium-doped fiber ring cavity for refractive index measurements is presented and experimentally demonstrated. This cavity ring includes a 1 × 3 coupler wherein one of the fiber output ports is used to increase the optical power of the system by means of an FBG used as a reflector. The other two output ports are used as a refractive index sensing head and reference port, respectively. An experimental demonstration of this proposed sensor system for the measurement of a distinct refractive index is presented.

A Dual-Wavelength Fiber Laser Sensor with Temperature and Strain Discrimination.

This work presents a dual-wavelength C-band erbium-doped fiber laser assisted by an artificial backscatter reflector. This fiber-based reflector, inscribed by femtosecond laser direct writing, was fabricated into a single mode fiber with a length of 32 mm. The dual-wavelength laser obtained, centered at 1527.7 nm and 1530.81 nm, showed an optical signal-to-noise ratio over 46 dB when pumped at 150 mW. Another feature of this laser was that the power difference between the two channels was just 0.02 dB, regardless of the pump power, resulting in a dual emission laser with high equalization. On the other hand, an output power level and a central wavelength instability as low as 0.3 dB and 0.01 nm were measured, in this order for both channels. Moreover, the threshold pump power was 40 mW. Finally, the performance of this dual-wavelength fiber laser enhanced with a random reflector for sensing applications was studied, achieving the simultaneous measurement of strain and temperature with sensitivities around 1 pm/µÎµ and 9.29 pm/°C, respectively.

Gamma Radiation-Induced Effects over an Optical Fiber Laser: Towards New Sensing Applications.

In the present work, the effect of gamma radiation on the performance of different types of erbium-doped fibers (EDFs) when they are used in a fiber ring cavity (FRC) configuration is studied. Several pieces of commercial EDF are gamma-ray irradiated with different doses to evaluate the output power variations over time. The influence of different doses, from 150 Gy to 1000 Gy, over the output power level measurement and their amplified spontaneous emission (ASE) are experimentally evaluated both in the C and L bands. By using an FRC configuration we can detect the presence of gamma radiation. We can also estimate the irradiation doses applied to EDFs by measuring the slope of the short-term emission power.

Virtual FBGs Using Saturable Absorbers for Sensing with Fiber Lasers.

The spectral narrowing of Fiber Bragg Gratings (FBGs) introduced by unpumped Er-doped fiber (EDF) was analyzed for fiber lasers (FL). Owing to spatial hole burning (SHB), the spectral response of a virtual FBG can be employed for narrowing the band pass filter employed to determine the lasing wavelength of laser cavities. A common FL was mounted to analyze the spectral stability of the method, and a FL sensor for strain and temperature measurements was experimentally characterized to determine the stability of the narrowing effect achieved by the unpumped EDF, which acts as a virtual FBG. The results exhibited remarkably good narrowing effects of the spectral response of uniform FBGs.

Vital signs: improving antibiotic use among hospitalized patients.

BACKGROUND: Antibiotics are essential to effectively treat many hospitalized patients. However, when antibiotics are prescribed incorrectly, they offer little benefit to patients and potentially expose them to risks for complications, including Clostridium difficile infection (CDI) and antibiotic-resistant infections. Information is needed on the frequency of incorrect prescribing in hospitals and how improved prescribing will benefit patients. METHODS: A national administrative database (MarketScan Hospital Drug Database) and CDC's Emerging Infections Program (EIP) data were analyzed to assess the potential for improvement of inpatient antibiotic prescribing. Variability in days of therapy for selected antibiotics reported to the National Healthcare Safety Network (NHSN) antimicrobial use option was computed. The impact of reducing inpatient antibiotic exposure on incidence of CDI was modeled using data from two U.S. hospitals. RESULTS: In 2010, 55.7% of patients discharged from 323 hospitals received antibiotics during their hospitalization. EIP reviewed patients' records from 183 hospitals to describe inpatient antibiotic use; antibiotic prescribing potentially could be improved in 37.2% of the most common prescription scenarios reviewed. There were threefold differences in usage rates among 26 medical/surgical wards reporting to NHSN. Models estimate that the total direct and indirect effects from a 30% reduction in use of broad-spectrum antibiotics will result in a 26% reduction in CDI. CONCLUSIONS: Antibiotic prescribing for inpatients is common, and there is ample opportunity to improve use and patient safety by reducing incorrect antibiotic prescribing. Implications for Public Health: Hospital administrators and health-care providers can reduce potential harm and risk for antibiotic resistance by implementing formal programs to improve antibiotic prescribing in hospitals.

Hemodynamic impact of isobaric levobupivacaine versus hyperbaric bupivacaine for subarachnoid anesthesia in patients aged 65 and older undergoing hip surgery.

BACKGROUND: The altered hemodynamics, and therefore the arterial hypotension is the most prevalent adverse effect after subarachnoid anesthesia. The objective of the study was to determine the exact role of local anesthetic selection underlying spinal anesthesia-induced hypotension in the elderly patient. We conducted a descriptive, observational pilot study to assess the hemodynamic impact of subarachnoid anesthesia with isobaric levobupivacaine versus hyperbaric bupivacaine for hip fracture surgery. DESCRIPTION: Hundred twenty ASA status I-IV patients aged 65 and older undergoing hip fracture surgery were enrolled. The primary objective of our study was to compare hemodynamic effects based on systolic blood pressure (SBP) and dyastolic blood pressure (DBP) values, heart rate (HR) and hemoglobin (Hb) and respiratory effects based on partial oxygen saturation (SpO2%) values. The secondary objective was to assess potential adverse events with the use of levobupivacaine versus bupivacaine. Assessments were performed preoperatively, at 30 minutes into surgery, at the end of anesthesia and at 48 hours and 6 months after surgery. Among intraoperative events, the incidence of hypotension was statistically significantly higher (p <0.05) in group BUPI (38.3%) compared to group LEVO (13.3%). There was a decrease (p <0.05) in systolic blood pressure (SBP) and diastolic blood pressure (DBP) at 30 minutes intraoperatively (19% in group BUPI versus 17% in group LEVO). SpO2% increased at 30 minutes after anesthesia onset (1% in group BUPI versus 1.5% in group LEVO). Heart rate (HR) decreased at 30 minutes after anesthesia onset (5% in group BUPI versus 9% in group L). Hemoglobin (Hb) decreased from time of operating room (OR) admission to the end of anesthesia (9.3% in group BUPI versus 12.5% in group LEVO). The incidence of red blood cell (RBC) transfusion was 13.3% in group BUPI versus 31.7% in group LEVO, this difference was statistically significant. Among postoperative events, the incidence of congestive heart failure (CHF) was significantly higher in group BUPI (8,3%). At 6 months after anesthesia, no differences were found. CONCLUSIONS: Given the hemodynamic stability and lower incidence of intraoperative hypotension observed, levobupivacaine could be the agent of choice for subarachnoid anesthesia in elderly patients.

[Methicillin-resistant Staphylococcus aureus (MRSA) isolation in breast abscesses in a Public Maternity]. / Aislamiento de Staphylococcus aureus meticilino resistente en abscesos de mama en una Maternidad Pública.

UNLABELLED: Mastitis and breast abscess in lactating women are risk factors for early breastfeeding cessation. This pathology is included in the group of skin and soft tissue infections. A descriptive study was performed with an advanced outlook. As of January 2007 through December 2011 a total of 137 breast abscesses were treated in our institution. We analyzed incidence, parity, postpartum days, risk factors, microbiological isolation and the adequacy of initial antibiotic treatment. In that period we observed a steady and significant increase in breast abscesses. Incidence from 0.19 to 0.84% in lactating women 2007 vs. 2011 p = 0.0001 IC 95% (-0.009; 0.003), 70.6% of them primiparous and a mean interval from delivery to breast abscess of 41.9 ± 35.8 days. The most frequent risk factors were sore nipples and breast engorgement. Staphylococcus aureus was isolated in 82.3 to 95.0%. Methicillin resistance was higher than 60%. These strains were susceptible to erythromycin, clindamycin, gentamicin, rifampicin, ciprofloxacin and trimethoprim-sulfamethoxazol. All the cases were surgically drained; the initial empirical treatment was inadequate in 60% of them, 90% of patients could maintain breast feeding after the procedure. IN CONCLUSION: these data emphasize the need to prevent risk factors associated to breast abscesses: sore nipples and breast engorgement. In order to determine the adequate antibiotic treatment, bacteriological studies are required at every collection because SAMR prevalence varies according to diverse populations and geographic location.

Bioactive compounds in Spanish extra virgin olive oils: Migration and stability according to the culinary technique used.

Extra virgin olive oil (EVOO) is a basic food of the Mediterranean diet and an important source of bioactive compounds, especially phenolic substances. The culinary techniques to which the oil is subjected before consumption cause the migration of these compounds, hence the importance of studying their stability before and after culinary treatment. We determined the behaviour of the phenols present in EVOO and its total antioxidant capacity before and after the use of various culinary techniques such as deep frying, boiling (in a water/oil mixture (W/O) and sauteing, observing that the study parameters varied according to the variety of oil and the culinary technique used. Significant statistical differences were observed between the different varieties of EVOO according to the culinary technique used. But this was not the case with respect to polyphenol content, for which no statistically significant differences were observed among the different varieties of EVOO according to the culinary techniques employed (p > 0.05), except with the Arbequina variety (p < 0.05). With respect to the individual polyphenols - tyrosol, p-vainillin, vanillic acid, gallic acid, trans-caffeic acid, ferulic acid and luteolin - our analysis shows that although there were differences in content between raw EVOO and EVOO treated with each of the culinary techniques, these differences were not statistically significant (p > 0.05). There were significant losses of oleocanthal with the W/O boiling technique, but content increases were observed following sauteing and deep frying with respect to raw EVOO. Total antioxidant capacity presented a similar pattern in all samples, with increases after sauteing and decreases after W/O boiling and deep frying. ABTS was the most suitable technique for determining antioxidant capacity in EVOO. In short, the behaviour of the bioactive compounds in EVOO depends on the temperature and the cooking medium used.

[Clinical guideline. Obstetrical hemorrhage in the second half of pregnancy]. / Guía de práctica clínica. Hemorragia obstétrica en la segunda mitad del embarazo.

Pregnancy at older ages and the increased frequency of caesarean births may increase the incidence of diseases associated with obstetric haemorrhage. Obstetric haemorrhage is the second leading cause of maternal mortality, preceded only by preeclampsia-eclampsia in Mexico and the Instituto Mexicano del Seguro Social. In recent years several studies have been conducted to improve the detection, diagnosis and treatment of women at risk of obstetric haemorrhage to reduce maternal and perinatal mortality. The objective of this clinical practice guideline is defining recommendations based in the best available evidence to standardize actions regarding the diagnosis and management of obstetric haemorrhage in hospital units.

Analysis and Screening of Commercialized Protein Supplements for Sports Practice.

Recent years have seen a rise in the popularity of the consumption of sports-related supplements. However, the hypothesis is raised that it is necessary to analyze the quality aspects of these supplements in relation to the information provided on the label, to avoid associated risks and obtain the greatest possible benefit from their consumption. Therefore, the aim of this study has been to carry out an analysis or screening of the protein supplements that are currently marketed in Spain. We analyzed the labels of 52 protein sports supplements available both in physical stores and online. The analysis consisted of addressing three relevant aspects considering the labeling: (a) the legislative framework in which the supplements are marketed, (b) the quality of the protein, and (c) the presence of other ingredients according to the specifications of the label. In the legislative context, there do not seem to be any specific regulations to guarantee consumer protection, which can lead to unfair practices and misleading advertising. Most of the supplements analyzed to comply with the requirements of their current regulations. However, claims about their benefits that are not allowed under European legislation have been found in some of them. Regarding composition and according to label information, the supplements have been found to provide a sufficient dose of protein in terms of recommended protein intake per serving. Regarding the presence of other ingredients and according to the information on the label, most of them, except for egg supplements, contain other ingredients. Colostrum was also found in one of the supplements evaluated. The conclusions of the study reveal that, due to a lack of knowledge or misleading advertising practices, supplements are often not used properly. The information provided is essential for both professionals and consumers to avoid the risks associated with consumption, such as unintentional doping, interactions between ingredients that reduce the quality of the supplement, and consumption of supplements inappropriately, among others.

Liquid level sensor based on dynamic Fabry-Perot interferometers in processed capillary fiber.

In this work, a novel optical fiber sensor capable of measuring both the liquid level and its refractive index is designed, manufactured and demonstrated through simulations and experimentally. For this, a silica capillary hollow-core fiber is used. The fiber, with a sensing length of 1.55 mm, has been processed with a femtosecond laser, so that it incorporates four holes in its structure. In this way, the liquid enters the air core, and it is possible to perform the sensing through the Fabry-Perot cavities that the liquid generates. The detection mode is in reflection. With a resolution of 4 µm (liquid level), it is in the state of the art of this type of sensor. The system is designed so that in the future it will be capable of measuring the level of immiscible liquids, that is, liquids that form stratified layers. It can be useful to determine the presence of impurities in tanks.

Migration of Avocado Virgin Oil Functional Compounds during Domestic Cooking of Eggplant.

Avocado virgin oil (AVO) was used during eggplant deep-frying, boil, and boil in a water-oil mixture (W/O). There were measured the contents of moisture, dry matter, fat, total (TPC) and ten individual phenols, antioxidant activity (ABTS and DPPH), and total sterols; as well as the profiles of eight fatty acids and fourteen sterols/stanols. The values of raw and processed foods were compared and studied with multivariate analysis. The antioxidant capacity of AVO lowered after deep frying but augmented in eggplant and water after all treatments. The TPC was steady in AVO and raised in fried eggplant. Thermal treatments added to the initial profiles of the AVO, eggplant and water, nine, eight, and four phenols, respectively. Percentages of the main fatty acids (oleic, palmitic and linoleic), and sterols (ß-sitosterol, campesterol, and Δ5-avenasterol), remained unchanged between the raw and treated AVO; and the lipidic fractions from processed eggplant. Cooking leads to the movement of hydrophilic and lipophilic functional compounds between AVO, eggplant and water. Migration of sterols and unsaturated fatty acids from AVO to eggplant during deep frying and W/O boiling improved the functional properties of eggplant by adding the high biological value lipophilic fraction to the naturally occurring polyphenols.

Long-range hybrid network with point and distributed Brillouin sensors using Raman amplification.

We propose a novel concept for hybrid networks that combine point and distributed Brillouin sensors in a cost-effective architecture that also deploys remote distributed Raman amplification to extend the sensing range. A 46-km proof-of-concept network is experimentally demonstrated integrating point vibration sensors based on fiber Bragg gratings and tapers with distributed temperature sensing along the network bus. In this network the use of Raman amplification to compensate branching and fiber losses provides a temperature resolution of 0.7 degrees C and 13 m. Moreover, it was possible to obtain good optical signal to noise ratio in the measurements from the four point vibration sensors that were remotely multiplexed in the network. These low-cost intensity sensors are able to measure vibrations in the 0.1 to 50 Hz frequency range, which are important in the monitoring of large infrastructures such as pipelines.

[Critical reading of clinical investigation reports in pregraduate students]. / Lectura crítica de informes de investigación clínica en estudiantes de pregrado.

OBJECTIVE: To evaluate the development of critical reading (CR) of clinical research texts (CRT) in medical students. METHODS: In 65 students an instrument for the evaluation of CR of CRT was applied. Four groups from three universities were studied: an academic excellence group (n = 21), B1 (n = 19) and B2 (n = 12), C (n = 13). The instrument had eight CRT with 150 items; 50 items to any of the following indicators: interpretation, judgment and proposition. The items were balanced in 50 % false and 50 % true. It was analyzed the global management degrade and by indicator. STATISTICAL ANALYSIS: Kruskal-Wallis and Mann-Whitney U test was used. RESULTS: Age 22 (median) 20-28 (range) years, gender 56.9 % women, without differences between the three universities. The global score was 50.5 (8 to 112). Group A had statistically significant higher results in global score and by indicator (p < 0.001) in relation with the other universities. According to the interpretation, judgment and proposition indicators, group A had the higher score. CONCLUSIONS: The results are similar to those observed in medical residents, because the development degrade for CR reading was low.

Active Tuberculosis Is Characterized by Highly Differentiated Effector Memory Th1 Cells.

Despite advances in diagnosing latent Mycobacterium tuberculosis infection (LTBI), we still lack a diagnostic test that differentiates LTBI from active tuberculosis (TB) or predicts the risk of progression to active disease. One reason for the absence of such a test may be the failure of current assays to capture the dynamic complexities of the immune responses associated with various stages of TB, since these assays measure only a single parameter (release of IFN-γ) and rely on prolonged (overnight) T cell stimulation. We describe a novel, semi-automated RNA flow cytometry assay to determine whether immunological differences can be identified between LTBI and active TB. We analyzed antigen-induced expression of Th1 cytokine mRNA after short (2- and 6-h) stimulation with antigen, in the context of memory T cell immunophenotyping. IFNG and TNFA mRNA induction was detectable in CD4+ T cells after only 2 h of ex vivo stimulation. Moreover, IFNG- and TNFA-expressing CD4+ T cells (Th1 cells) were more frequent in active TB than in LTBI, a difference that is undetectable with conventional, protein-based cytokine assays. We also found that active TB was associated with higher ratios of effector memory to central memory Th1 cells than LTBI. This effector memory phenotype of active TB was associated with increased T cell differentiation, as defined by loss of the CD27 marker, but not with T cell exhaustion, as determined by PD-1 abundance. These results indicate that single-cell-based, mRNA measurements may help identify time-dependent, quantitative differences in T cell functional status between latent infection and active tuberculosis.

[Educative strategy evaluation to improve critical reading skills on clinical research texts in second year gyneco-obstetrics residents]. / Evaluación de una estrategia educativa para mejorar la aptitud para la lectura crítica de textos de investigación clínica en residentes de ginecoobstetricia de segundo año.

BACKGROUND: The educative models and strategies to achieve a significant learning have a wide variety. The development of clinical aptitude for clinical research papers lecture has an important place to maintain the physician actualized and for resident formation. OBJECTIVE: To evaluate the degree of development of the aptitude for the reading of clinical research articles in 2nd grade residents of the gynecology and obstetrics speciality alter an educative strategy. MATERIAL AND METHODS: In 16 2nd year gynecology and obstetrics residents, a previously validated instrument was applied for the evaluation of critical lecture of clinical research articles in general medicine previous and after and educative strategy. Statistical analysis was with Kruskal-Wallis analysis of variance. Also Wilcoxon test was used to assess the differences between baseline and final results. RESULTS: The median of age was 27 (24-31) years, gender 56.3% women and 43.8% men. A statistically significant increase in global score was observed after the educative strategy. After it only there was a significant increase in the indicator to interpret. After evaluating the domain degrees according to the indicator to interpret, in baseline evaluation it predominated the very low level and at the final evaluation the very low and low levels. In the indicator to judge at baseline the majority were in the very low level, and at the end in very low and low levels. According to the indicator to propose at baseline all were in the level expected by hazard, and at the end a minimal proportion was at very low level. CONCLUSION: These results traduce a discrete improvement in critical lecture process, which makes to consider the educative strategy that was used, since the objective to improve critical lecture capacity was not achieved.

Automatic counting of fungiform papillae by shape using cross-correlation.

The determination of the number of fungiform papillae (FP) on the human tongue is important for taste sensitivity studies. Most of the time, the counting of the FP is done manually. In this paper we propose a novel algorithm to count the FP using shape characteristics measured by cross-correlation. The accuracy of the algorithm is evaluated by counting the FP manually on the same images and then doing a statistical analysis. A Poisson regression model is fitted using maximum likelihood. The result is that the algorithm counts are very similar to the human experts. Another advantage of the algorithm is its facility of use, velocity and that it can work on a plain tongue image, without the need to stain the tongue as is usual in manual counting.