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Purpose: The pericapsular nerve group (PENG) block provides satisfactory postoperative analgesia without hampering motor function for total hip arthroplasty (THA); however, unexpected motor block has been observed clinically. It is unknown whether this motor block is related to the dose of ropivacaine. We aimed to conduct a prospective randomized trial to test whether reducing the volume or concentration of ropivacaine was better for less motor block after PENG block. Patients and Methods: Ninety-nine patients with fracture or femoral head necrosis scheduled for THA were randomly allocated to receive 20 mL 0.5% ropivacaine (Group A), 20 mL 0.25% ropivacaine (Group B), and 10 mL 0.5% ropivacaine (Group C). The primary outcome was the incidence of postoperative quadriceps motor block at 6 hours. Secondary outcomes were the incidence of postoperative quadriceps motor block at 0, 12, 24 and 48 hours; pain scores on the numeric rating scale (NRS) at all postoperative time points (0, 6, 12, 24, and 48 hours); the time to first walk; the incidence of rescue analgesia; side effects such as dizziness, ache, nausea, and vomiting; and patient satisfaction. Results: Compared with Group A, Group C resulted in a lower incidence of quadriceps motor block at 0 hours, 6 hours and 12 hours postoperatively (P < 0.05), while Group B only resulted in a lower incidence of motor block at 12 hours postoperatively (P < 0.05). No intergroup differences were found in terms of postoperative pain scores, the incidence of rescue analgesia, adverse events or patient satisfaction (P > 0.05). Conclusion: A higher incidence of motor blockade was observed when 20 mL of 0.5% ropivacaine was administered, which was mainly caused by the excessive volume. Therefore, we recommend performing PENG block with 10 mL 0.5% ropivacaine.
RESUMO
OBJECTIVE: This study used electroencephalography to explore the behavioral and electrophysiological effects of task interruption on performance. BACKGROUND: Task interruption is known to harm work performance, especially on working memory-related tasks. However, most studies pay little attention to cognitive processes by exploring brain activity and ignore the cumulative effect of sequential interruptions. METHOD: Thirty-four healthy participants performed a spatial 2-back in three conditions: (1) interruptions with simple math questions, (2) suspensions with prolonged fixation cross, and (3) a pure 2-back. The measured outcomes comprise performance data, ERP amplitudes, EEG power, and subjective workload. RESULTS: Work performance decreased in the resumption trials, and cumulative interruptions had a more destructive effect on performance. EEG results showed that the P2 and P3 amplitudes induced by the 2-back task significantly increased after interruptions; theta and alpha power increased after interruptions. The P3 amplitude and alpha power induced by interruptions were significantly higher than that induced by suspensions. CONCLUSION: Behavioral data revealed the disruptive effect of interruptions on postinterruption performance and the cumulative effect of interruptions on accuracy. Changes in ERP amplitudes and EEG power indicate the mechanisms of attention reallocation and working memory during interruptions. Larger P3 amplitudes and alpha power after interruptions than after suspensions suggested the inhibition of irrelevant information. These results may support the memory for goals model and improve the understanding of the effects of interruption on working memory. APPLICATION: Focusing upon the mechanisms at play during the interruption process can support interruption management to ensure work safety and efficiency.
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NiO/ZnO gas-sensing nanotube materials were prepared by electrospinning. The structure and morphology of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energydispersive X-ray detection (EDX) and Brunauer-Emmett-Teller (BET) analysis. The template, PAN (peroxyacetyl nitrate) fibers, was completely removed, as evidenced by the EDX results. The final NiO/ZnO composite materials were composed of hexagonal wurtzite ZnO and cubic NiO and exhibited hollow tubular structures. In the composites, p-n heterojunctions were formed at the interface of NiO and ZnO. The results of gas sensitivity tests showed that the incorporation of NiO considerably improved the gas sensitivity of ZnO to ethanol. When the doping ratio was 0.125 mol/mol, the composites exhibited the highest sensitivity to ethanol (100.92 at 300 °C) and showed high selectivity.
RESUMO
Objectives: To observe the changes of cerebral blood flow parameters showed by perfusion-weighted magnetic resonance imaging (PWI) in patients after aneurysmal subarachnoid hemorrhage (aSAH) and to investigate the correlation between cerebral hemodynamics and cerebral vasospasm ( CVS ). Methods: A total of 38 patients with aSAH ( ≤7 d) were selected for cerebral angiography. The severity of CVS was observed and PWI was performed. The parameters of regional cerebral blood flow (rCBF) , regional cerebral blood volume (rCBV) , mean transit time (MTT) , and time to peak (TTP) were collected in the territories of anterior cerebral artery, middle cerebral artery, and basal ganglia. The correlation between these parameters and CVS was analyzed. Results: DSA showed that 28 of the 38 patients had vasospasm at least in one branch, 9 of them had mild vasospasm; 10 had moderate vasospasm, and 9 had severe vasospasm; 10 did not find any CVS. Circled digit twoAs compared with the control group,the rCBF and rCBV in ACA, MCA, and BSGL territories in the severe vasospasm group were decreased, and there were significant differences ( P < 0.05 to P < 0.01 ) , while the rCBF and rCBV in all the blood supply territories in the non-, mild, moderate, and severe vasospasm groups had a tendency of reduction, however, the degrees of reduction were different. As compared with the control group, the TTP and MTT had an increasing tendency in the ACA, MCA and BSGL territories in the mild, moderate, and severe vasospasm groups; among them, there was significant difference between the moderate and severe vasospasm groups ( P < 0. 05 to P < 0.01). Circled digit threeThe severity of CVS was negatively correlated with rCBF and rCBV, and it was positively correlated with TTP and MTT. Conclusions: PWI may quantitatively provide the information of cerebral blood flow perfusion. Among the parameters of rCBF, rCBV, TTP, and MTT in all the blood supply territories collected by PWI, the parameters of TTP and MTT had better consistency with the severity of CVS.
