35 research outputs found
Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.
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
Influence of Olive Fruit Storage in Bags on Oil Quality and Composition of Volatile Compounds
The composition of olive oil volatile components depends on genetic factors, ripening
grade of the fruit, fruit storage and processing conditions. Storage of olives in reticular or
plastic bags is still a frequently used practice that has negative effects on oil quality, particularly
on sensory characteristics. The changes of volatile compounds during this procedure
were determined using headspace solid phase microextraction (HS-SPME). The method
was optimised as regards sample conditioning and extraction time, and verified by
testing the repeatability and linearity of the response. The main changes during fruit storage
in bags are increase of methanol and ethanol concentration and decrease of 1-penten-
3-one, trans-2-hexenal and cis-3-hexenyl acetate concentration. The changes in plastic
bags are more evident and significant differences between the two types of storage are
established
Chuck System for Integrated IR-Based Temperature Measurement in Rotational Grinding of Sapphire Wafers
Single crystalline sapphire wafers are used as a substrate for semiconductor and
optoelectronic applications like gallium nitride-based LED light sources. In the
optimization of the manufacturing chain, rotational grinding plays a mayor role by
substituting the conventional lapping process in order to reduce cost intensive efforts
in downstream polishing steps. Due the material properties of the sapphire and in
particular its hardness of 9 on the Mohs Scale however, it is difficult to establish a
stable finishing process. For this reason, the detection of in-process variables like the
grinding temperature distribution in the contact zone between the wafer and the
grinding wheel are of significant interest. On the one hand, the acquired data increase
process understanding, enhancing grinding wheel and process development. On the
other hand, real-time processing of the measurement data enables direct control of the
process in order to achieve optimum stability. Within this paper, a novel chuck
system for the measurement of contact zone temperatures is presented. The general
behaviour of the realized system is examined in preliminary calibration tests and
grinding tests are performed to prove the feasibility of the chuck system under
common machining conditions
IR-Based Temperature Measurement in Rotational Grinding of Sapphire Wafers
Single crystalline sapphire wafers are used as a substrate for semiconductor applications like
gallium nitride-based white LEDs. In the optimization of the manufacturing chain, rotational grinding can
play a mayor role by substituting the conventional lapping process and reducing cost intensive efforts in
downstream polishing steps. Due the material properties and in particular the hardness of sapphire, however,
grinding process development is difficult. For this reason, the measurement of in-process variables like
contact zone temperatures is of significant interest. In this paper, a concept and experimental setup for IRbased
temperature measurement that utilizes the optical properties of sapphire is presented. The system
behavior of the realized test setup is examined in calibration tests. The results of successfully performed
grinding tests are presented to prove the feasibility of the measurement concept
Impact of harmonic imaging on transthoracic echocardiographic identification of infective endocarditis and its complications
Objective: To evaluate the comparative diagnostic value of harmonic imaging (HI) in the assessment of patients with suspected infective endocarditis (IE). Setting: Tertiary referral centre. Design: 139 consecutive patients were evaluated with three imaging modalities: transthoracic echocardiography with fundamental imaging (FI); HI; and transoesophageal echocardiography (TOE). Image quality was assessed for each modality by semiquantitative scoring (0, poor, to 3, excellent). Presence, dimension, and characteristics of vegetations were assessed separately for each imaging modality, as well as presence of abscesses. Results: 35 patients had definite IE. TOE was positive in 33 patients, HI in 28, and FI in 12 (p < 0.001 for FI v HI and v TOE). Mean image quality was 1.4 (0.7) for FI, 2.1 (0.6) for HI (p < 0.01 v FI), and 2.6 (0.4) for TOE (p < 0.001 v HI). The association between FI and TOE findings was Φ = 0.35 (χ(2) = 17.57, p = 0.0014) and between HI and TOE it was Φ = 0.95 (χ(2) = 125.72, p < 0.0001; p < 0.0001 v FI). The global echo score of vegetations was 7.1 (3.3) with FI, 8.5 (3.4) with HI, and 11.3 (3.9) with TOE (p < 0.001 v HI). Compared with TOE, FI identified only one of seven abscesses (sensitivity 14%) and HI identified two of seven abscesses (sensitivity 28%). Conclusions: HI provides an accurate assessment of suspected IE. TOE achieves superior definition of IE related abnormalities
Evaluation and Origin of Residual Stress in Hybrid Metal and Extrusion Bonding and Comparison with Friction Stir Welding
Hybrid metal and extrusion bonding (HYB) is an emerging solid-state welding technique that was developed about ten years ago. HYB exploits the fundamental idea of the well-established friction stir welding (FSW) technology, but a filler material is employed to enhance control of the microstructure and the mechanical properties of the joint. HYB and FSW allow joining to be performed at lower temperatures than classical fusion welding methods. Still, thermal gradient effects seem impossible to be entirely avoided, thus leading to residual stress within the weld region and neighbouring material. Although the FSW-induced residual stress evaluation has been extensively studied and understood, the evaluation and interpretation of HYB-induced residual stress have not been tackled so far. In the present paper, a quantitative investigation on residual stress and its origin in HYB was carried out for the first time. Specifically, a 4 mm thick AA6082-T6 HYB and a 4 mm thick AA6082-T6 FSW butt welds were considered. For the particular case of HYB, an AA6082-T4 was used as the filler material. In both cases, the full-field longitudinal residual stress was experimentally assessed using the Contour Method. The results showed that the HYB joint yields a higher magnitude of tensile residual stress compared to that of the FSW counterpart. A physical explanation for this difference in magnitude was attributed to the lower yield stress point exhibited by the filler material. Furthermore, the analysis revealed peak values of residual stress as high as 205±25 MPa and 165±15 MPa, for the HYB and FSW joint, respectively. Despite this, a similar distribution of residual stress across the weld was observed in both cases. An additional qualitative analysis on the transverse distortion of the welds outlined a pronounced undesired “V-like” deformation of the HYB joint of approximately 1.4°. By contrast, the FSW joint seemed not to show any perceptible bend