38 research outputs found

    Annealing-Induced Modifications in Physicochemical and Optoelectronic Properties of Ag-Doped Nanostructured CdS Thin Films

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    The Ag-doped nanostructured CdS thin films are grown by simple, cost effective chemical ion exchange technique at room temperature on ITO-coated glass substrate. These as grown thin films are annealed at 100, 200, 300, and 400°C in air atmosphere for 1 hour. To study the effect of annealing on physicochemical and optoelectronic properties, these as grown and annealed thin films are characterized for structural, compositional, morphological, optical, and electrical properties. X-ray diffraction (XRD) pattern reveals polycrystalline nature of these thin films with increase in crystallite size from 6.4 to 11.2 nm, from XRD the direct identification of Ag doping in CdS thin films cannot be judged, while shift in characteristics peak position of CdS is observed. The Raman spectrum represents increase in full width at half maxima and intensity of characteristic peak, confirming the material modification upon annealing treatment. Presence of Cd, Ag, and S in energy dispersive X-ray analysis spectra (EDAX) confirms expected elemental composition in thin films. Scanning electron microscopy (SEM) images represent grain growth and agglomeration upon annealing. Red shift in optical absorbance strength and energy band gap values from 2.28 to 2.14 eV is obtained. I-V response obtained from as grown and annealed thin films shows an enhancement in photosensitivity from 72% to 96% upon illumination to 100 mW/cm2 light source

    Dietary n-3 fatty acids have suppressive effects on mucin upregulation in mice infected with Pseudomonas aeruginosa

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    International audienceMucin hypersecretion and mucus plugging in the airways are characteristic features of chronic respiratory diseases like cystic fibrosis (CF) and contribute to morbidity and mortality. In CF, Pseudomonas aeruginosa superinfections in the lung exacerbate inflammation and alter mucus properties. There is increasing evidence that n-3 polyunsaturated fatty acids (PUFAs) exhibit anti-inflammatory properties in many inflammatory diseases while n-6 PUFA arachidonic acid (AA) favors inflammatory mediators such as eicosanoids prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) that may enhance inflammatory reactions. This suggests that n-3 PUFAs may have a protective effect against mucus over-production in airway diseases. Therefore, we hypothesized that n-3 PUFAs may downregulate mucins expression. We designed an absolute real-time PCR assay to assess the effect of a 5-week diet enriched either with n-3 or n-6 PUFAs on the expression of large mucins in the lungs of mice infected by P. aeruginosa. Dietary fatty acids did not influence mucin gene expression in healthy mice. Lung infection induced an increase of the secreted gel-forming mucin Muc5b and a decrease of the membrane bound mucin Muc4. These deregulations are modulated by dietary fatty acids with a suppressive effect of n-3 PUFAs on mucin (increase of Muc5b from 19-fold up to 3.6 x 10(5)-fold for the n-3 PUFAs treated group and the control groups, respectively, 4 days post-infection and decrease of Muc4 from 15-fold up to 3.2 x 10(4)-fold for the control and the n-3 PUFAs treated groups, respectively, 4 days post-infection). Our data suggest that n-3 PUFAs enriched diet represents an inexpensive strategy to prevent or treat mucin overproduction in pulmonary bacterial colonization

    Noninvasive biophotonic imaging for studies of infectious disease

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    According to World Health Organization estimates, infectious organisms are responsible for approximately one in four deaths worldwide. Animal models play an essential role in the development of vaccines and therapeutic agents but large numbers of animals are required to obtain quantitative microbiological data by tissue sampling. Biophotonic imaging (BPI) is a highly sensitive, nontoxic technique based on the detection of visible light, produced by luciferase-catalysed reactions (bioluminescence) or by excitation of fluorescent molecules, using sensitive photon detectors. The development of bioluminescent/fluorescent microorganisms therefore allows the real-time noninvasive detection of microorganisms within intact living animals. Multiple imaging of the same animal throughout an experiment allows disease progression to be followed with extreme accuracy, reducing the number of animals required to yield statistically meaningful data. In the study of infectious disease, the use of BPI is becoming widespread due to the novel insights it can provide into established models, as well as the impact of the technique on two of the guiding principles of using animals in research, namely reduction and refinement. Here, we review the technology of BPI, from the instrumentation through to the generation of a photonic signal, and illustrate how the technique is shedding light on infection dynamics in vivo

    Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

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    BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

    Resistive Ammonia Gas Sensor Based on Non-Stoichiometric Copper Sulfide Thin Films

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    Resistive ammonia gas sensor is fabricated by using solution growth technique deposited copper sulfide (Cu1.8S) thin films. Structural and opto-electronic properties of the films are studied by X-ray diffraction, atomic force microscopy, optical absorbance and electrical resistance. Ammonia gas sensor response measured from 20 to 500 ppm concentration at room temperature (300 K). The sensor response is increases with gas concentration

    Surface Morphology Dependent Copper Sulphide Ammonia Gas Sensor Working at Room Temperature: Effect of SHI Irradiation

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    We report the synthesis of copper sulphide (CuS) nano-pillars on copper sulphide thin film surface by using swift heavy ion (SHI) irradiation. Thin films of CuS are irradiated with 100 MeV gold ions at fluence varying from 1011 to 5 ´ 1012 ions/cm2. These nanostructures grown on the surface of copper sulphide has been used for the detection of ammonia gas at room temperature. The time dependent surface conductance measurements show the utility of copper sulphide for the detection of ammonia. It is observed that the response of the material is highly influenced by the irradiation fluence

    <span style="font-size: 22.5pt;mso-bidi-font-size:15.5pt;font-family:"Times New Roman","serif"; mso-bidi-font-weight:bold">Effect of preparation procedures on long-term performance of SnO<sub><span style="font-size:17.5pt;mso-bidi-font-size:10.5pt; font-family:"Times New Roman","serif";mso-bidi-font-weight:bold">2</span></sub><span style="font-size:17.5pt;mso-bidi-font-size:10.5pt;font-family:"Times New Roman","serif"; mso-bidi-font-weight:bold"> <span style="font-size:22.5pt;mso-bidi-font-size: 15.5pt;font-family:"Times New Roman","serif";mso-bidi-font-weight:bold">thin film sensing layers deposited with different methodologies </span></span></span>

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    749-766<span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">There is an increasing demand for SnO<span style="font-size:12.5pt; mso-bidi-font-size:5.5pt;font-family:" arial","sans-serif""="">2 semiconducting gas sensors for several monitoring applications that have sensitivity, selectivity and reliability on a long-term scale. The present paper reviews the long-term performance of SnO2 thin film sensing layers, which strongly depend on the preparation procedures and different thin film deposition techniques. <span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">The stability and reliability are very important for tin dioxide based gas sensor devices, when these are to be integrated with standard CMOS circuitry. The stability in the output of the thin film sensing layer is very essential to implement reliable integrated sensor device, because a small drift in the baseline leads to a large change in the biasing current in the subsequent <span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">signal processing circuit. The long-term stable behaviour of the SnO2 thin film gas sensor has been found in the literature, and it depends on the thin film deposition conditions, annealing temperature, time, ambient, and noble metal/metal oxide dopant. It can be seen from the literature that, sensitivity and stability of SnO<span style="font-size:13.0pt;mso-bidi-font-size: 6.0pt;font-family:" times="" new="" roman","serif""="">2 thin film were strongly affected with variation in the crystallite (grain) size and growth procedures. The thin films were deposited by chemical methods such as, screen-printing, sol-gel, spray pyrolysis, etc. and physical methods such as, RGTO, sputtering, PLA, etc. with the grain size varying from 5 to 50 nm with annealing temperatures varying in the range 500-800<span style="font-size:20.0pt; mso-bidi-font-size:13.0pt;font-family:" times="" new="" roman","serif""="">°C and with noble metal/metal oxide dopants. Such type treated SnO2 thin films have a little change in sensitivity but the sensing layer has much higher, long time operational stability. </span
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