One-pot synthesis of D-π-D-π-D type hole-transporting materials for perovskite solar cells by sequential C-H (hetero)arylations.

We report a step-saving new access to D-π-D-π-D type oligoaryls through one-pot sequential C-H (hetero)arylations. Conventionally, these oligomers were prepared by Stille or Suzuki coupling reactions that required prefunctionalization steps. The facilely synthesized linear oligomers were fabricated in perovskite-based solar devices as efficient hole transporters, exhibiting a power conversion efficiency of up to 15.4%.

Direct C-H Arylation Meets Perovskite Solar Cells: Tin-Free Synthesis Shortcut to High-Performance Hole-Transporting Materials.

In contrast to the traditional multistep synthesis, we demonstrate herein a two-step synthesis shortcut to triphenylamine-based hole-transporting materials (HTMs) through sequential direct C-H arylations. These hole-transporting molecules are fabricated in perovskite-based solar cells (PSCs) that exhibit promising efficiencies up to 17.69 %, which is comparable to PSCs utilizing commercially available 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-OMeTAD) as the HTM. This is the first report describing the use of step-saving C-H activations/arylations in the facile synthesis of small-molecule HTMs for perovskite solar cells.

Changes in endotracheal tube cuff pressure during laparoscopic surgery in head-up or head-down position.

BACKGROUND: The abdominal insufflation and surgical positioning in the laparoscopic surgery have been reported to result in an increase of airway pressure. However, associated effects on changes of endotracheal tube cuff pressure are not well established. METHODS: 70 patients undergoing elective laparoscopic colorectal tumor resection (head-down position, n = 38) and laparoscopic cholecystecomy (head-up position, n = 32) were enrolled and were compared to 15 patients undergoing elective open abdominal surgery. Changes of cuff and airway pressures before and after abdominal insufflation in supine position and after head-down or head-up positioning were analysed and compared. RESULTS: There was no significant cuff and airway pressure changes during the first fifteen minutes in open abdominal surgery. After insufflation, the cuff pressure increased from 26 ± 3 to 32 ± 6 and 27 ± 3 to 33 ± 5 cmH2O in patients receiving laparoscopic cholecystecomy and laparoscopic colorectal tumor resection respectively (both p < 0.001). The head-down tilt further increased cuff pressure from 33 ± 5 to 35 ± 5 cmH2O (p < 0.001). There six patients undergoing colorectal tumor resection (18.8%) and eight patients undergoing cholecystecomy (21.1%) had a total increase of cuff pressure more than 10 cm H2O (18.8%). There was no significant correlation between increase of cuff pressure and either the patient's body mass index or the common range of intra-abdominal pressure (10-15 mmHg) used in laparoscopic surgery. CONCLUSIONS: An increase of endotracheal tube cuff pressure may occur during laparoscopic surgery especially in the head-down position.

Performance of central venous catheterization by medical students: a retrospective study of students' logbooks.

BACKGROUND: Medical students often learn the skills necessary to perform a central venous catheterization in the operating room after simulator training. We examined the performance of central venous catheterization by medical students from the logbooks during their rotation in department of anesthesiology. METHODS: From the logbooks of medical students rotating in our department between January 2011 and June 2012, we obtained the kind and the number of central venous catheterization students had done, the results of the procedures whether they were success or failed, the reasons of the failures, complications, and the student self-reported confidence and satisfaction of their performance. RESULTS: There were 93 medical students performed 875 central venous catheterizations with landmark guidance on patients in the operating theater, and the mean number of catheterizations performed per student was 9.4 ± 2.0, with a success rate of 67.3%. Adjusted for age, sex, body mass index, surgical category, ASA score and insertion site, the odds of successful catherization improved with cumulative practice (odds ratio 1.10 per additional central venous catheterization performed; 95% confidence interval 1.05-1.15). The major challenge students encountered during the procedure was the difficulty of finding the central veins, which led to 185 catheterizations failed. The complication rate of central venous catheterization by the students was 7.8%, while the most common complication was puncture of artery. The satisfaction and confidence of students regarding their performance increased with each additional procedure and decreased significantly if failure or complications had occurred. CONCLUSION: A student logbook is a useful tool for recording the actual procedural performance of students. From the logbooks, we could see the students' performance, challenges, satisfaction and confidence of central venous catheterization were improved through cumulative clinical practice of the procedure.

Comparison of single coracoclavicular suture fixation and hook plate for the treatment of acute unstable distal clavicle fractures.

BACKGROUND: Surgical managements are recommended for unstable distal clavicle fractures because of a high incidence of nonunion. A variety of methods have been previously reported, but there is no current consensus regarding which method is the most suitable. METHODS: Between December 2004 and August 2010, we treated 68 patients with Neer type IIB distal clavicle fractures using single coracoclavicular suture fixation with Mersilene tape (M group) or clavicular hook plate (H group). Sixty-eight patients were followed at least 24 months (mean, 37.9 months). We retrospectively compared the functional outcome, parameters, and perioperative course of the two treatments. Statistical analysis was performed with independent sample t test and chi-square test. RESULTS: The M group presented significantly less operation time (P = 0.005) and intra-operative blood loss (P = 0.010) than the H group. The mean University of California at Los Angeles (UCLA) shoulder rating scale, Oxford shoulder score, VAS scale, and satisfaction score revealed no significant difference between the M group and the H group. The M group had better range of motion in the operated shoulder during forward flexion and abduction at 3 and 6 months postoperatively. However, the range of motion at 1 and 2 years after operation revealed almost the same results. Two acromial osteolysis and one acromial fracture were noted in the H group and one superficial wound infection and one frozen shoulder in the M group during follow-up. Finally, there was no significant difference in the complication rate between the two groups, and all fractures achieved union clinically at final follow-up. CONCLUSIONS: Both single coracoclavicular suture fixation and clavicular hook plate offered effective treatment in acute unstable distal clavicle fractures. However, single coracoclavicular suture fixation with Mersilene tape provided early recovery of shoulder motion and avoided further morbidity of the acromion.

Analgesic efficacy of tramadol/acetaminophen and propoxyphene/acetaminophen for relief of postoperative wound pain.

BACKGROUND/PURPOSE: Weak opioid combined with acetaminophen (APAP) has been proven to provide better analgesic efficacy and cause fewer complications than either drug alone. However, there are questions about whether different opioids, tramadol and propoxyphene, provide similar efficacy or safety. Thus, we investigated Ultracet (37.5 mg tramadol/325 mg APAP) and Depain-X (65 mg propoxyphene/650 mg APAP). The primary aims of this study were to compare the analgesic efficacy and adverse effects of single-dose oral Ultracet versus Depain-X in acute postoperative pain. MATERIALS AND METHODS: This was a randomized, open-label, active-controlled parallel study on patients with postsurgical pain. Sixty patients who sustained moderate postsurgical pain (visual analog scale(3)3 cm) after undergoing implantation of venous access were randomized to two groups to receive either Ultracetor Depain-X for postoperative analgesia. Assessment items included pain intensity and pain relief ratings at the first 4 hours, and adverse events. RESULTS: There were initially 107 patients who were enrolled in this trial, but up to 45 (42.1%) of them were withdrawn during the study. In these 62 patients who complied with treatment (Ultracet: Depain-X = 29: 33), pain relief scale indicated that Ultracet could provide a better analgesic effect than Depain-X provided at 1 hour (p < 0.05). At 4 hours, the pain score in the Ultracet group was significantly lower than that in the Depain-X group (p < 0.05). Adverse events, such as drowsiness, dizziness, and skin itching did not differ in both groups. CONCLUSION: Among patients with mild to moderate postoperative wound pain, single-dose Ultracet can provide slightly better analgesic efficacy than Depain-X in terms of onset and duration. Depain-X is no longer marketed in Europe, America, Taiwan and other countries, therefore, Ultracet can serve as a good substitute for treating postoperative pain.

Anterior mitral leaflet perforation identified by real time three-dimensional transesophageal echocardiography.

With its unique en face view, real time three-dimensional transesophageal echocardiography has been reported to be more precise than conventional two-dimensional studies in evaluating mitral regurgitation etiology, and can locate diseased segments correctly. We present a case with severe mitral regurgitation due to anterior mitral leaflet perforation. Intraoperative real time three-dimensional transesophageal echocardiography demonstrated its value in diagnosis and surgical planning for this perforation, which had not been identified preoperatively. This technique should be applied more widely for dedicated mitral valve assessment in clinical practice.