ETTc pressure estimated by palpation with personal experience is often much higher than measured or what may be optimal. Proper control of ETTc pressure by a manometer helped reduce ETT-related postprocedural respiratory complications such as cough, sore throat, hoarseness, and blood-streaked expectoration even in procedures of short duration (1-3 hours).
Desflurane was associated with a faster early recovery than sevoflurane after general anesthesia in elderly patients. However, recovery of cognitive function was similar with both volatile anesthetics.
been reported. And for tandem solar cells, the PCE has reached 17%. [22] However, the vast majority of those device performances were obtained with layer-thicknesses at around 100 nm [23][24][25][26][27][28][29] and decreased drastically with the increase of the active layer thickness, which limits their application in the roll to roll large-scale solution printing technology. [30,31] Furthermore, 20%-40% of the incident photon flux were wasted in such a active layer thickness, [32] which directly limits the short circuit current density (J sc ) of the corresponding OSCs. Thus, it is necessary to develop high efficiency OSCs with tolerance of the active layer thickness. However, a lot of research work have proved that the charge collection efficiency of a device is inversely proportional to the square of the film thickness of the active layer. [33,34] It was reflected in the decline of fill factor (FF) with the increase of film thickness. Also, the J sc will decrease due to the severe bimolecular recombination. [35,36] Thus, it is still a challenge to obtain high efficiency devices with active layer thickness tolerance. To date, in the reported cases with active layer thickness tolerance, most are based on fullerene derivative acceptors and it has been found that the donor materials with high crystallinity and balanced mobility with fullerene derivative acceptors manifested better performance with high film thickness. [35][36][37][38] Compared with fullerene derivatives based OSCs, it is much more challenging to realize thick-film NFAs OSCs with high performance since the electron mobilities of NFAs are usually lower than that of fullerene derivative acceptors. [39,40] Thus, the charge transport and collection process in those NFA based thick films are not efficient. So far, great attentions have been drawn on the NFA based thick film OSCs and much progress have been made. For examples, Yip and co-workers reported devices based on PffBT4T-2OD:EH-IDTBR and realized a PCE of 9.1% with an active layer thickness of 300 nm by optimizing device architectures to overcome the space-charge effects. [41] Zhang and co-workers reported devices based on PM6:IDIC with PCEs of 11.9% under the film thickness of 150 nm and 11.3% under the condition of 255 nm condition. Although the device performance is good enough, the cases with thicker active layers Developing efficient organic solar cells (OSCs) with relatively thick active layer compatible with the roll to roll large area printing process is an inevitable requirement for the commercialization of this field. However, typical laboratory OSCs generally exhibit active layers with optimized thickness around 100 nm and very low thickness tolerance, which cannot be suitable for roll to roll process. In this work, high performance of thick-film organic solar cells employing a nonfullerene acceptor F-2Cl and a polymer donor PM6 is demonstrated. High power conversion efficiencies (PCEs) of 13.80% in the inverted structure device and 12.83% in the conventional structure device are achi...
It is a great challenge to simultaneously improve the two tangled parameters, open circuit voltage (Voc) and short circuit current density (Jsc) for organic solar cells (OSCs). Herein, such a challenge is addressed by a synergistic approach using fine‐tuning molecular backbone and morphology control simultaneously by a simple yet effective side chain modulation on the backbone of an acceptor–donor–acceptor (A–D–A)‐type acceptor. With this, two terthieno[3,2‐b]thiophene (3TT) based A–D–A‐type acceptors, 3TT‐OCIC with backbone modulation and 3TT‐CIC without such modification, are designed and synthesized. Compared with the controlled molecule 3TT‐CIC, 3TT‐OCIC shows power conversion efficiency (PCE) of 13.13% with improved Voc of 0.69 V and Jsc of 27.58 mA cm−2, corresponding to PCE of 12.15% with Voc of 0.65 V and Jsc of 27.04 mA cm−2 for 3TT‐CIC–based device. Furthermore, with effective near infrared absorption, 3TT‐OCIC is used as the rear subcell acceptor in a tandem device and gave an excellent PCE of 15.72%.
The dominant hole transport material (HTM) in state-of-the-art perovskite solar cells (PSCs) is Spiro-OMeTAD, which needs to be doped using hydrophilic dopants to improve its hole mobility and conductivity, resulting in inferior device stability. Here, we propose an effective molecular design strategy to construct dopant-free polymer HTMs by selecting four structurally related polymers and investigating their structureproperty relationship. It is found that the donor and acceptor units with longitudinal conjugate extension, such as BDT-T and BDD, could not only enhance the planarity of the conjugated polymer backbone and tune the energy levels but also promote the face-on orientation, resulting in superior charge extraction and transport. The optimized device utilizing dopant-free polymer HTM shows a high open-circuit voltage of 1.19 V and a champion efficiency of 24.04 % with greatly improved operational stability, making it among the best performance PSCs based on dopant-free HTMs.
ObjectivesClinical observation, as well as randomized controlled trials, indicated an increasing rate of postoperative cognitive dysfunction (POCD) with increasing depth of general anesthesia. However, the findings are subject to bias due to varying degree of analgesia. In this trial, we compared the rate of POCD between patients receiving light versus high anesthesia while holding analgesia comparable using nerve block.MethodsElderly patients (≧60 years) receiving elective total knee replacement were randomized to receive the surgery under general anesthesia at BIS 40–50 (LOBIS group) or BIS 55–65 (HIBIS group). The femoral nerve and the sciatic nerve were blocked under ultrasonic guidance in all patients before induction. Cognitive performance was assessed with Montreal cognitive assessment (MoCA) at the baseline and 1d, 3d, and 7d after the surgery. POCD was defined by Z score of >1.96 using cross‐reference. The extubation time and recovery time were also compared.ResultsA total of 66 patients were randomized; 60 (n = 30 per group) completed trial as the protocol specified. POCD occurred in six patients (20%) in the LOBIS group vs. in one patient (3.3%) in the HIBIS group (Figure 3, p = .04). In all seven cases, the diagnosis of POCD was based on MoCA assessment on 1d after the surgery. Assessment in 3d and 7d after surgery did not reveal POCD in any case. Extubation time was longer in the LOBIS group (12.16 ± 2.58 vs. 5.77 ± 3.01 min in the HIBIS group (p < .001)). The time of comeback of directional ability was 13.47 ± 3.14 and 6.17 ± 3.23 min in the LOBIS and HIBIS groups, respectively (p < .001).ConclusionsIn elderly patients receiving a total knee replacement, lighter anesthesia could reduce the rate of POCD with complete analgesia during surgery.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.