186 research outputs found

    CO2 sensing with chemoresistive Nd2O2CO3 sensors - Operando insights

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    AbstractIn this work the sensing of Nd2O2CO3-based chemoresistive CO2 sensor was investigated combining DRIFT and DC-resistance measurements. Besides the already reported effect of CO2 exposure, we found that exposure to CO determines comparable effects and that the presence of oxygen in the background is not important. The humidity significantly influences the response for both gases. The spectroscopic results reveal that the exposure to both CO and CO2 consumes the water-related surface species – the rooted-hydroxyls being the electrically active one – and increases the concentration of carbonates; the decrease of the rooted-hydroxyls is probably the cause of the resistance increase

    TECHNOLOGY FOR ORGANIC WEED CONTROL

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    In recent years, crop maintenance works have become a major challenge for organic farming systems, where the application of chemical treatments is totally forbidden. The effect of weeds on crops varies according to pedoclimatic, biological or technological parameters, the resulting damages being both quantitative and qualitative. By weed control, we aim to prevent their competition in order to obtain maximum crop yields.Among the methods of thermal weed control, used as an alternative to chemical weeding, steam or hot water-based ones have been increasingly used as they provide an efficient, environmentally friendly and economical way of removing harmful plants.This paper presents a technology for the maintenance of medicinal and aromatic plant organic crops, based on the use of innovative equipment for weed thermal control by using hot water

    Tratamentul chirurgical al Hiperplaziei Prostatice Benigne (HPB)

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    Summary The work is dedicated to comparative analysis of results of surgery treatment in patients with Benign Prostate Hyperplasia. The 543 patients with untreated prostate adenoma (exposed toadenoma removal - 415 patients, and transurethral resection - 128 patients). The analysis of the results demonstrated, that the rate and the character of intra- and post- operation complications depends considerably on rational choice of surgical intervenfion method (transvesical or transurethral) and quality of its realization. In present TUR remains the main method in the treatment of BPH, possessing many advantages and at the same time presenting many possibilities of simultaneous treatment of other diseases, which accompany BPH. Transvesical adenomaectomy remains a method of BPH treatment, having more narrow concrete indications: adenoma of great size and its combination with great or multiple urinary bladder stones

    Reconstructia sanului dupa diferitele proceduri chirurgicale adresate cancerului mamar

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    Spitalul Clinic de Urgenţă “Bagdasar-Arseni” Bucureşti, România, Spitalul Clinic de urgenţă “Sf. Pantelimon” Bucureşti, România, Spitalul Judeţean de Urgenţă Piteşti, România, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Introducere. Dintre neoplaziile intalnite la femeie, cancerul mamar o reprezinta pe cea mai frecventa incidenta acestuia fiind in crestere in ultimele decenii. Chirurgia de conservare a sanului este acum larg acceptata drept tratamentul de electie in cancerul mamar.Actualmente, cancerul mamar este abordat in echipe pluridisciplinare, reconstructia dupa diferitele tipuri de interventii de exereza fiind preferata in majoritatea cazurilor. Se are in vedere reconstructia volumului sanului, simetrizarea sanului nou format cu cel controlateral si reconstructia placii areolo-mamare. Material si metoda. Lucrarea de fata are la baza studiul retrospectiv al unui numar de 7 cazuri de cancer mamar tratate in Spitalul Clinic de Urgenta “Bagdasar-Arseni” in intervalul Iunie 2008 – Iunie 2011. Au fost luate in calcul atat cazurile la care s-au facut in cadrul aceleasi interventii chirurgicale, cat si cazurile la care reconstructia s-a facut la un anumit interval distanta.Rezultate. Rezultatele au fost bune in cadrul ambelor tehnici – reconstructie imediata dupa ablatie si reconstructie la distanta – insa procentul complicatiilor asociate a fost mai mare pentru reconstructia la distanta, in mare masura datorita remanierilor tisulare aparute intre cele doua interventii chirurgicale. Mortalitatea a fost 0, iar in cadrul morbiditatii am intalnit un caz cu necroza parcelara ce a necesitat o reinterventie pentru grefare si un caz de limforagie persistenta, care odata devenit cronic, a necesitat indepartarea protezei de silicon. Concluzii.-Tehnica de reconstructie este una dificila si minutioasa, al carui rezultat favorabil este dependent atat de alegerea unei tehnici de ablatie potrivita urmata de una de reconstructie individuala cat si de colaborarea interdisciplinara intre chirurgul de chirurgie generala, chirurgul plastician si medicul oncolog- In urma cazurilor prezentate si a rezultatelor foarte bune obtinute optam pentru reconstructia imediata urmata de tratamentul chimioterapeutic specific.-Din experienta noastra consideram extrem de importante indicatia chirurgicala, tehnica pentru care se opteaza, acordul asupra abordului utilizat al membrilor echipei pluridisciplinare si urmarirea postoperatorie atenta

    Rhodium oxide surface-loaded gas sensors

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    In order to increase their stability and tune-sensing characteristics, metal oxides are often surface-loaded with noble metals. Although a great deal of empirical work shows that surface-loading with noble metals drastically changes sensing characteristics, little information exists on the mechanism. Here, a systematic study of sensors based on rhodium-loaded WO₃, SnO₂, and In₂O₃—examined using X-ray diffraction, high-resolution scanning transmission electron microscopy, direct current (DC) resistance measurements, operando diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, and operando X-ray absorption spectroscopy—is presented. Under normal sensing conditions, the rhodium clusters were oxidized. Significant evidence is provided that, in this case, the sensing is dominated by a Fermi-level pinning mechanism, i.e., the reaction with the target gas takes place on the noble-metal cluster, changing its oxidation state. As a result, the heterojunction between the oxidized rhodium clusters and the base metal oxide was altered and a change in the resistance was detected. Through measurements done in low-oxygen background, it was possible to induce a mechanism switch by reducing the clusters to their metallic state. At this point, there was a significant drop in the overall resistance, and the reaction between the target gas and the base material was again visible. For decades, noble metal loading was used to change the characteristics of metal-oxide-based sensors. The study presented here is an attempt to clarify the mechanism responsible for the change. Generalities are shown between the sensing mechanisms of different supporting materials loaded with rhodium, and sample-specific aspects that must be considered are identified

    Self-activated ultrahigh chemosensitivity of oxide thin film nanostructures for transparent sensors

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    One of the top design priorities for semiconductor chemical sensors is developing simple, low-cost, sensitive and reliable sensors to be built in handheld devices. However, the need to implement heating elements in sensor devices, and the resulting high power consumption, remains a major obstacle for the realization of miniaturized and integrated chemoresistive thin film sensors based on metal oxides. Here we demonstrate structurally simple but extremely efficient all oxide chemoresistive sensors with similar to 90% transmittance at visible wavelengths. Highly effective self-activation in anisotropically self-assembled nanocolumnar tungsten oxide thin films on glass substrate with indium-tin oxide electrodes enables ultrahigh response to nitrogen dioxide and volatile organic compounds with detection limits down to parts per trillion levels and power consumption less than 0.2 microwatts. Beyond the sensing performance, high transparency at visible wavelengths creates opportunities for their use in transparent electronic circuitry and optoelectronic devices with avenues for further functional convergence.open181

    Epidemiology, practice of ventilation and outcome for patients at increased risk of postoperative pulmonary complications

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    BACKGROUND Limited information exists about the epidemiology and outcome of surgical patients at increased risk of postoperative pulmonary complications (PPCs), and how intraoperative ventilation was managed in these patients. OBJECTIVES To determine the incidence of surgical patients at increased risk of PPCs, and to compare the intraoperative ventilation management and postoperative outcomes with patients at low risk of PPCs. DESIGN This was a prospective international 1-week observational study using the ‘Assess Respiratory Risk in Surgical Patients in Catalonia risk score’ (ARISCAT score) for PPC for risk stratification. PATIENTS AND SETTING Adult patients requiring intraoperative ventilation during general anaesthesia for surgery in 146 hospitals across 29 countries. MAIN OUTCOME MEASURES The primary outcome was the incidence of patients at increased risk of PPCs based on the ARISCAT score. Secondary outcomes included intraoperative ventilatory management and clinical outcomes. RESULTS A total of 9864 patients fulfilled the inclusion criteria. The incidence of patients at increased risk was 28.4%. The most frequently chosen tidal volume (VT) size was 500 ml, or 7 to 9 ml kg1 predicted body weight, slightly lower in patients at increased risk of PPCs. Levels of positive end-expiratory pressure (PEEP) were slightly higher in patients at increased risk of PPCs, with 14.3% receiving more than 5 cmH2O PEEP compared with 7.6% in patients at low risk of PPCs (P < 0.001). Patients with a predicted preoperative increased risk of PPCs developed PPCs more frequently: 19 versus 7%, relative risk (RR) 3.16 (95% confidence interval 2.76 to 3.61), P < 0.001) and had longer hospital stays. The only ventilatory factor associated with the occurrence of PPCs was the peak pressure. CONCLUSION The incidence of patients with a predicted increased risk of PPCs is high. A large proportion of patients receive high VT and low PEEP levels. PPCs occur frequently in patients at increased risk, with worse clinical outcome

    Epidemiology, practice of ventilation and outcome for patients at increased risk of postoperative pulmonary complications: LAS VEGAS - An observational study in 29 countries

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    BACKGROUND Limited information exists about the epidemiology and outcome of surgical patients at increased risk of postoperative pulmonary complications (PPCs), and how intraoperative ventilation was managed in these patients. OBJECTIVES To determine the incidence of surgical patients at increased risk of PPCs, and to compare the intraoperative ventilation management and postoperative outcomes with patients at low risk of PPCs. DESIGN This was a prospective international 1-week observational study using the ‘Assess Respiratory Risk in Surgical Patients in Catalonia risk score’ (ARISCAT score) for PPC for risk stratification. PATIENTS AND SETTING Adult patients requiring intraoperative ventilation during general anaesthesia for surgery in 146 hospitals across 29 countries. MAIN OUTCOME MEASURES The primary outcome was the incidence of patients at increased risk of PPCs based on the ARISCAT score. Secondary outcomes included intraoperative ventilatory management and clinical outcomes. RESULTS A total of 9864 patients fulfilled the inclusion criteria. The incidence of patients at increased risk was 28.4%. The most frequently chosen tidal volume (V T) size was 500 ml, or 7 to 9 ml kg−1 predicted body weight, slightly lower in patients at increased risk of PPCs. Levels of positive end-expiratory pressure (PEEP) were slightly higher in patients at increased risk of PPCs, with 14.3% receiving more than 5 cmH2O PEEP compared with 7.6% in patients at low risk of PPCs (P ˂ 0.001). Patients with a predicted preoperative increased risk of PPCs developed PPCs more frequently: 19 versus 7%, relative risk (RR) 3.16 (95% confidence interval 2.76 to 3.61), P ˂ 0.001) and had longer hospital stays. The only ventilatory factor associated with the occurrence of PPCs was the peak pressure. CONCLUSION The incidence of patients with a predicted increased risk of PPCs is high. A large proportion of patients receive high V T and low PEEP levels. PPCs occur frequently in patients at increased risk, with worse clinical outcome.</p
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