Yttrium orthoaluminate nanoperovskite doped with Tm3+ ions as upconversion optical temperature sensor in the near-infrared region.

The thermal sensing capability of the Tm3+-doped yttrium orthoaluminate nanoperovskite in the infrared range, synthetized by a sol-gel method, was studied. The temperature dependence of the infrared upconverted emission bands located at around 705 nm (3F2,3→3H6) and 800 nm (3H4→3H6) of YAP: Tm3+ nanoperovskite under excitation at 1210 nm was analyzed from RT up to 425 K. Calibration of the optical sensor has been made using the fluorescence intensity ratio technique, showing a high sensitivity in the near-infrared compared to other trivalent rare-earth based optical sensors working in the same range. In addition, a second calibration procedure of the YAP: Tm3+ optical sensor was performed by using the FIR technique on the emission band associated to the 3H4→3H6 transition in the physiological temperature range (293-333 K), showing a very high relative sensitivity compared with other rare-earth based optical temperature sensors working in the physiological range. Moreover, the main advantage compared with other optical sensors is that the excitation source and the upconverted emissions do not overlap, since they lie in different biological windows, thus allowing its potential use as an optical temperature probe in the near-infrared range for biological applications.

Portable IR dye laser optofluidic microresonator as a temperature and chemical sensor.

A compact and portable optofluidic microresonator has been fabricated and characterized. It is based on a Fabry-Perot microcavity consisting essentially of two tailored dichroic Bragg mirrors prepared by reactive magnetron sputtering deposition. The microresonator has been filled with an ethanol solution of Nile-Blue dye. Infrared laser emission has been measured with a pump threshold as low as 0.12 MW/cm2 and an external energy conversion efficiency of 41%. The application of the device as a temperature and a chemical sensor is demonstrated. Small temperature variations as well as small amount of water concentrations in the liquid laser medium are detected as a shift of the resonant laser modes.

Upconversion emission obtained in Yb(3+)-Er(3+) doped fluoroindate glasses using silica microspheres as focusing lens.

An intensity enhancement of the green upconversion emission from a codoped Er(3+)-Yb(3+) fluoroindate glass has been obtained by coating the glass surface with silica microspheres (3.8 µm diameter). The microspheres focus an incoming beam (λ ≈ 950 nm) on the surface of the fluoroindate glass. The green emission (λ ≈ 545 nm) of the Er(3+) ions located in the microsphere focus was measured with a microscope in reflection mode, being the peak intensity 4.5 times the emission of the bare substrate. The transversal FWHM of the upconversion spot was experimentally determined by deconvolution with the experimental Point Spread Function of the system, obtaining a value of 309 nm. This value is in good agreement with Finite-Difference Time-Domain simulations taking into account the magnification of the image due to the microsphere.

High-sensitivity fluorescence lifetime thermal sensing based on CdTe quantum dots.

The potential use of CdTe quantum dots as luminescence nano-probes for lifetime fluorescence nano-thermometry is demonstrated. The maximum thermal sensitivity achievable is strongly dependent on the quantum dot size. For the smallest sizes (close to 1 nm) the lifetime thermal sensitivity overcomes those of conventional nano-probes used in fluorescence lifetime thermometry.

Whispering gallery modes in a glass microsphere as a function of temperature.

Microspheres of Nd3+ doped barium titano silicate glass were prepared and the whispering gallery mode resonances were observed in a modified confocal microscope. A bulk sample of the same glass was calibrated as temperature sensor by the fluorescence intensity ratio technique. After that, the microsphere was heated by laser irradiation process technique in the microscope and the surface temperature was estimated using the fluorescence intensity ratio. This temperature is correlated with the displacement of the whispering gallery mode peaks, showing an average red-shift of 10 pm/K in a wide range of surface temperatures varying from 300 K to 950K. The limit of resolution in temperature was estimated for the fluorescence intensity ratio and the whispering gallery mode displacement, showing an improvement of an order of magnitude for the second method.

Whispering-gallery modes in glass microspheres: optimization of pumping in a modified confocal microscope.

Whispering-gallery modes (WGMs) on Nd3+-doped glass microspheres with a radius of ∼15 µm were measured in a modified confocal microscope, where a dual spatial resolution in both excitation and detection zones was possible. As an alternative to the standard excitation mechanism by an evanescent wave, we used an efficient pumping/detecting scheme, focusing a laser in the microsphere and exciting the Nd3+ ions, whose fluorescent emission produces the WGMs. We have also measured the generated WGMs by changing the detection zone, where higher amplitude resonances were found when exciting in the center and detecting at the edge of the microsphere.

Nanocrystals distribution inside the writing lines in a glass matrix using Argon laser irradiation.

Localized modification in strontium barium niobate glass doped with Ho(3+) under laser irradiation has been carried out. The preliminary samples of this study have been fabricated by the melt quenching method and doped with 2.5% mol of Ho(3+). A 3.5W cw multiline Ar-laser has been focused and shifted in a line during laser irradiation. The formation of Strontium Barium Niobate nanocrystals has been confirmed by X-ray diffraction, atomic force microscope image and fluorescence. They have been localized in the irradiation line and change the optical properties of the sample. These nanocrystals have been obtained due to the excitation of the Ho(3+) ions which under nonradiative processes produced the heating of the sample. In this work, it has been demonstrated that the diffusion of the Nb(5+) ions to the border of the irradiated line controls the growth of the nanocrystals in the sample.

Role of the local structure and the energy trap centers in the quenching of luminescence of the Tb3+ ions in fluoroborate glasses: a high pressure study.

The concentration and pressure dependent luminescence properties of the Tb(3+) ions in a lithium fluoroborate glasses have been studied by analyzing the deexcitation processes of the (5)D(4) level at ambient conditions as well as a function of pressure up to 35 GPa at room temperature. The luminescence spectra of Tb(3+) ions have been measured as a function of pressure and observed a continuous redshift as well as a progressive increase in the magnitude of the crystal-field splittings for the (5)D(4)-->(7)F(3,4,5) transitions. Monitoring the (5)D(4)-->(7)F(5) transition, the luminescence decay curves have been measured and analyzed in order to understand the dynamics of the deexcitation of the Tb(3+) ions in these glasses. At ambient conditions a nonexponential behavior has been found for doping concentrations as low as 0.1 mol % of Tb(4)O(7), although no cross-relaxation channels exist to explain this behavior. The modelization of the energy transfer processes surprisingly shows that the nonexponential character of the decay curves of the (5)D(4) level with concentration or with pressure has to be ascribed to energy transfer to traps without migration of energy between Tb(3+) ions. For all the experimental situations the nonexponential character of the decay curves is well described by the generalized Yokota-Tanimoto model with a dipole-dipole interaction between the Tb(3+) ions and the nearby luminescence quenching traps. The luminescence properties observed with releasing pressure are slightly different to those obtained while increasing pressure suggesting a local structural hysteresis in the lithium fluoroborate glass matrix giving rise to the generation of a new distribution of environments for the Tb(3+) ions.

SEOM clinical guideline for secondary prevention (2019).

Cancer is one of the major public health problems in our society. It is estimated that more than 18 million new cases are diagnosed worldwide every year; 280,000 in Spain. Incidence in following a growing trend. This epidemic could be controlled with research into new treatments and, above all, with adequate prevention. Primary prevention could prevent avoid up to half of all cases. For many others, secondary prevention is essential, as it make diagnosis possible in the stages of the disease when it is easily curable. These guidelines present the scientific evidence regarding secondary prevention in tumors in which its use is well-accepted: breast, cervical, colorectal, prostate, lung, ovarian, melanoma, and gastric cancer.

Growth of nanocrystals in a Nd3+-Yb3+ codoped oxyfluoride glass by laser irradiation.

A local nanocrystalline formation in a Neodymium-Ytterbium codoped oxyfluoride glass has been obtained. It has been studied the intense emissions around 880 and 975 nm originated from the 4F3/2(Nd3+) and 2F5/2(Yb3+) levels when the glass structure changes to a glass ceramic structure due to the irradiation of the laser beam. The emission spectra before and after the irradiation with 2900 mW reveals that the desvitrification process made by the laser power beam has been successfully achieved. The intensities and lifetime changes of these levels inside and outside the hole made by the laser damage have been analyzed. These results confirm that nanocrystals of betaPbF2 have been created by the laser action confirming that the transition from glass to glass ceramic has been completed. These results are in agreement with the bulk spectroscopic measurements.

Slow magnetic relaxation mechanisms in erbium SIMs.

The magnetic properties of two similar Er(3+) complexes have been investigated. [Er(tpm)3(bipy)] (Htpm = 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione and bipy = 2,2'-bipyridine) displays thermally activated slow relaxation of magnetisation under a zero direct-current (DC) field. Under an applied HDC field of 1000 G, [Er(tpm)3(bipy)] exhibits two thermally activated processes with energy barriers of 9 and 40 K, while [Er(tfa)3(bipy)] (Htfa = 4,4,4-trifluoro-1-(2-furyl)-1,3-butanedione) shows only one activated process with a barrier of 15 K. Both compounds are luminescent in the solid state, emitting in the near IR region.

Heart and lung transplantation for terminal cystic fibrosis. A 4 1/2-year experience.

From among 112 patients with cystic fibrosis who were assessed for heart-lung transplantation, 83 were accepted. Twenty-six died while awaiting heart-lung transplantation and 32 had the operation. The management and the outcome of these 32 patients is reported. Survival, infection, and rejection rates among these patients were compared with those of 61 patients without cystic fibrosis who underwent heart-lung transplantation between 1984 and 1990. The cumulative survival rate was 72.29% +/- 94.91% at 1 year and 55.59% +/- 7.50% at 3 years. The mortality rate was slightly higher in the group with cystic fibrosis during the first year after the operation but it was lower at 3 years. The difference, however, could have been due to chance alone (p = 0.308). The same was true for the prevalence of rejection (up to 6 months: chi 2 = 1.8141, p = 0.17), and infection (up to 6 months: chi 2 = 2.20, p = 0.14), between the two groups. It is concluded that cystic fibrosis does not constitute an additional risk in terms of survival and morbidity after heart-lung transplantation.

An audit of the assessment and management of patients admitted to Christchurch Hospital with chronic obstructive pulmonary disease.

AIM: To audit the assessment and management of patients admitted to hospital with chronic obstructive pulmonary disease (COPD) during three months of the winter of 1992. METHODS: Consensus management guidelines were developed as the basis for the audit. Consecutive cases were audited by review of the case notes. Half were admitted initially under a respiratory physician and half under a general physician. Ninety-five cases were audited. RESULTS: The overall standard of medical assessment was adequate but a number of deficiencies were identified. The mean duration of stay in hospital was nine days. In the emergency department the use of pulse oximetry in preference to arterial blood gas analysis led to failure to diagnose significant ventilatory failure in five cases. Initial assessment by junior medical staff failed to include comment about level of consciousness in 50% of cases and chest hyperinflation in 40%. Oxygen therapy was given in 87% of cases, but was not prescribed in one third and was often not adequately monitored. Peak flow monitoring was performed on admission in 74% of cases and arterial blood gas measurement in 81%. Over 90% of patients were given nebulised bronchodilator therapy with both nebulised ipratropium bromide and salbutamol. Antibiotics were given in 77% of cases. Corticosteroids were given in 95% of cases, usually orally. Sedatives were prescribed inappropriately in six cases where there was acute ventilatory failure. Four patients died in hospital, none unexpectedly. Three patients were mechanically ventilated and all survived to leave hospital. There was no discharge summary in the case records in 29% of cases. CONCLUSIONS: Standards of assessment and treatment were adequate. Several areas were identified where improvements are required, particularly in the prescribing and monitoring of oxygen therapy. Hospital-wide guidelines for the management of COPD are to be developed.

Asthma management at Christchurch Hospital: compliance with guidelines.

AIM: To audit compliance with guidelines for the assessment and management of adult patients admitted to Christchurch Hospital with acute asthma. METHODS: An asthma admission form and management guidelines, based on international consensus statements, were designed for use by resident staff at Christchurch Hospital. Compliance with these guidelines was audited during the winter of 1994 by means of retrospective case record review. RESULTS: One hundred and forty three admissions were screened. The form was used in 99 patients (69%), of which 97 had records available for audit. Sixty two patients were admitted under general medical services and 35 under respiratory specialist services. The median age was 34 years (range 14-84) and 77% were female. The history including interval status was adequately documented in over 95% of cases. Peak flow rate was recorded on admission in 93 patients (96%) and spirometry in 62 (64%). During the acute phase of treatment 528 items were prescribed, of which 382 (72%) were appropriate according to the guidelines. The major area (55%) of nonguideline prescribing was the use of nebulised ipratropium in addition to salbutamol for mild or moderate asthma. Written evidence of asthma education was present in 42 (43%). In 34 patients (35%) there was specific reference to the introduction of an asthma action plan. Of the 33 smokers only 17 appeared to have been given smoking cessation advice. Discharge prescribing complied with the guidelines in 71%. The most common variation from the guidelines for discharge therapy related to the manner of prednisone dose reduction. The readmission rate at 1 month was 11%. CONCLUSIONS: The introduction of an asthma admission form enhanced the quality of clinical data gathering by junior staff. Compliance with management guidelines was adequate. Specific sections pertaining to the use of chest radiographs, arterial blood gases and the prescribing of ipratropium and prednisone will be reviewed in updated guidelines.

House dust mite and cat allergen levels in domestic dwellings in Christchurch.

AIMS: To quantify the levels of Dermatophagoides pteronyssinus allergen (Der p I) and Felis domesticus allergen (Fel d I) in domestic dwellings in Christchurch and to assess possible relationships with housing characteristics. METHODS: Domestic dwellings (n = 93) were randomly selected and housing characteristics documented during the summer of 1994/95. Dust samples were obtained from the floor of the living room (LR) and bedroom (BR) and from the bed by standard vacuuming methods. The predominant mite species were determined and D pteronyssinus and F domesticus levels quantified. RESULTS: D pteronyssinus was the predominant (95%) species. D pteronyssinus allergen levels [geomean (95% confidence intervals) were 3.5(2.5-4.8) micrograms/g in LR, 10.1(7.5-13.7) micrograms/g in BR and 5.7(4.3-7.6) micrograms/g in the bed. F domesticus allergen levels were significantly higher (p < 0.001) in houses with cats than without cats [median (range) 93.2 (3.3-1227.2) micrograms/g and 2.9 (0.4-214.8) micrograms/g respectively]. Higher LR D pteronyssinus allergen levels were found in houses classified as having high indoor humidity and in houses situated in geographically damp locations. CONCLUSIONS: Domestic D pteronyssinus and F domesticus allergen levels in Christchurch are comparable with those found in other climatically similar locations. D pteronyssinus allergen levels are associated with both indoor and outdoor humidity factors.

Cat allergen levels in public places in New Zealand.

AIMS: Cat allergen (Fel d 1) is a known risk factor for asthma. Studies have demonstrated Fel d 1 in both public buildings and domestic dwellings where cats have never been. The aims of this study were to measure reservoir Fel d 1 levels in public buildings in New Zealand, to examine determinants of these levels and to compare them with previously measured domestic levels. METHODS: Dust was obtained in two centres (Wellington and Christchurch) from hotels, hospitals, rest homes, churches, primary schools, childcare centres, cinemas, bank head offices and aeroplanes; and from North Island ski lodges. Measurements of temperature and relative humidity were taken. Information was collected on building characteristics. Fel d 1 levels (microg/g of fine dust) for floors (n=203), beds (n=64) and seats (n=24) were expressed as geometric means (95% confidence intervals). RESULTS: Detectable Fel d 1 levels were found in 95% of floor samples, 91% of bed samples and 100% of seat samples. Fel d 1 levels [geometric mean (95% confidence intervals)] were significantly higher on cinema and domestic aircraft seats [36.8 (20.8-65.3) microg/g and 33.3 (28.0-39.7) microg/g respectively] than on floors [3.6 (2.5-5.1) microg/g and 2.4 (1.8-3.0) microg/g respectively]. Floor Fel d 1 levels in the public buildings sampled were lower than those of domestic dwellings without cats [0.9 (0.6-1.4) microg/g vs 1.7 (1.2-2.4)] microg/g in Wellington and [2.0 (1.6-2.6) microg/g vs 4.0 (2.7-6.0] microg/g in Christchurch. After controlling for potential confounders, floor Fel d 1 levels were higher with carpeted floors (p<0.001) and lower in banks and hospitals (p<0.001). CONCLUSION: Fel d 1 levels in public buildings are low in New Zealand public places except for cinema and domestic aircraft seats where all but one sample had Fel d 1 levels potentially high enough to precipitate asthma symptoms in sensitised individuals.

Nosocomial pneumonia in adult general medical and surgical patients at Christchurch Hospital.

AIMS: To determine the incidence, microbial cause, and outcome of nosocomial pneumonia in adult general medical and surgical patients at Christchurch Hospital. METHOD: A one-year prospective study of consecutive patients developing nosocomial pneumonia in a university-affiliated hospital. Expanded diagnostic laboratory testing was undertaken to identify the microbial cause of pneumonia. RESULTS: We recruited 126 patients, which represented an incidence of 6.1 per 1,000 admissions. Only 52 (41%) patients submitted sputum that satisfied the cytological screening criteria for testing. A microbial cause was identified in 47 cases (37%): the most common was Legionella spp. (sixteen cases), followed by Influenza A (six cases) and Staphylococcus aureus (four cases). We did not identify an environmental source of the Legionella species. Fourteen patients (11%) died as a consequence of pneumonia and nearly all of these had significant comorbidity. Renal impairment, alcohol excess, and severity of pneumonia were the most powerful predictors of a fatal outcome by univariate analysis. CONCLUSIONS: In most patients we did not identify a microbial cause of pneumonia; when we did, Legionella species were the most common, although this micro-organism has a long incubation period so some subjects may have acquired it before admission. These results guide preventative efforts, diagnostic testing and selection of antimicrobial therapy for nosocomial pneumonia in our hospital.

[Combination heart-lung transplantation in children: 4-year experience in London]. / Gecombineerde hart-longtransplantatie bij kinderen: 4 jaar ervaring in Londen.

Since 1987, 21 children under 16 years of age have undergone combined heart and lung transplantation at Great Ormond Street Hospital, London. All children had terminal pulmonary or cardiopulmonary disease. Eight children died one day to 21 months after operation. Actuarial survival was 76% (SEM 10) at 1 year and 60% (SEM 12) at 3 and 4 years after transplantation. 13 children were alive, and all took part in all age-appropriate activities.

Active layer solution-processed NIR-OLEDs based on ternary erbium(III) complexes with 1,1,1-trifluoro-2,4-pentanedione and different N,N-donors.

Using a fluorinated 1,1,1-trifluoro-2,4-pentanedione (Htfac) ligand and either 2,2'-bipyridine (bipy), bathophenanthroline (bath) or 5-nitro-1,10-phenanthroline (5NO2phen) as an ancillary ligand, three new ternary erbium(iii) octacoordinated complexes have been synthesized. The single crystal structures of the new complexes (namely [Er(tfac)3(bipy)], [Er(tfac)3(bath)] and [Er(tfac)3(5NO2phen)]) have been determined and their properties have been investigated by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and thermodynamic analysis. After ligand-mediated excitation of these complexes in the UV, they all show the characteristic near-infrared (NIR) luminescence of the corresponding Er(3+) ion at 1532 nm. The same emission in the C-band transmission window can also be obtained from the solution-processed organic light-emitting diodes (OLEDs) with structure: glass/ITO/PEDOT:PSS/[Er(tfac)3(N,N-donor)]/Ca/Al. In spite of the fact that the photoluminescence intensity of [Er(tfac)3(5NO2phen)] is stronger than those of [Er(tfac)3(bipy)] and [Er(tfac)3(bath)], the best electroluminescence results correspond to the OLED based on the [Er(tfac)3(bath)] complex, as a consequence of the superior electron transport capabilities of bathophenanthroline.