A Novel Staggered Double-Segmented Grating Slow-Wave Structure for 340 GHz Traveling-Wave Tube.

In this paper, a novel staggered double-segmented grating slow-wave structure (SDSG-SWS) is developed for wide-band high-power submillimeter wave traveling-wave tubes (TWTs). The SDSG-SWS can be considered as a combination of the sine waveguide (SW) SWS and the staggered double-grating (SDG) SWS; that is, it is obtained by introducing the rectangular geometric ridges of the SDG-SWS into the SW-SWS. Thus, the SDSG-SWS has the advantages of the wide operating band, high interaction impedance, low ohmic loss, low reflection, and ease of fabrication. The analysis for high-frequency characteristics shows that, compared with the SW-SWS, the SDSG-SWS has higher interaction impedance when their dispersions are at the same level, while the ohmic loss for the two SWSs remains basically unchanged. Furthermore, the calculation results of beam-wave interaction show that the output power is above 16.4 W for the TWT using the SDSG-SWS in the range of 316 GHz-405 GHz with a maximum power of 32.8 W occurring at 340 GHz, whose corresponding maximum electron efficiency is 2.84%, when the operating voltage is 19.2 kV and the current is 60 mA.

An Updated Systematic Review and Meta-analysis of Duloxetine for Knee Osteoarthritis Pain.

OBJECTIVE: We conducted the updated systematic review and meta-analysis of the best available quantitative and qualitative evidence to evaluate the effects and safety of duloxetine for the treatment of knee osteoarthritis (OA) pain. METHODS: A comprehensive literature search used 3 English and 4 Chinese biomedical databases from inception through July 10, 2020. We included randomized controlled trials of duloxetine with intervention duration of 2 weeks or longer for knee OA. The primary outcome was pain intensity measured by Brief Pain Inventory and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale. Secondary outcome measurements included 36-Item Short Form Health Survey, Patient's Global Impression of Improvement, Clinical Global Impressions of Severity, and adverse events (AEs). The quality of all included studies was evaluated using the Cochrane risk-of-bias criteria. The review was registered in the PROSPERO (CRD 42020194072). RESULTS: Six studies totaling 2059 patients met the eligibility criteria. Duloxetine had significant reductions in Brief Pain Inventory 24 hours average pain (mean difference [MD]=-0.74; 95% confidence interval [CI], -0.92 to -0.57; P<0.00001; I2=13%; 5 trials; 1695 patients); patient general activity (MD=-0.76; 95% CI, -0.96 to -0.56; P<0.00001; I2=0%; 5 trials; 1694 patients) WOMAC physical function subscale (MD=-4.22; 95% CI, -5.14 to -3.30; P<0.00001; I2=26%; 5 trials; 1986 patients); Patient's Global Impression of Improvement (MD=-0.48; 95% CI, -0.58 to -0.37; P<0.00001; I2=29%; 5 trials; 1741 patients); and Clinical Global Impressions of Severity (MD=-0.34; 95% CI, -0.44 to -0.24; P<0.00001; I2=0%; 4 trials; 1178 patients) compared with placebo control. However, no difference on WOMAC pain subscale (standard mean difference=-1.68; 95% CI, -3.45 to 0.08; P=0.06; I2=100%; 3 trials; 1104 patients) and in serious AEs (risk ratio=0.92; 95% CI, 0.40-2.11; P=0.84; I2=0%; 5 trials; 1762 patients) between duloxetine and placebo. Furthermore, duloxetine failed to show superior effects for improving the life quality and demonstrated more treatment-emergent AEs. CONCLUSION: Duloxetine may be an effective treatment option for knee OA patients but further rigorously designed and well-controlled randomized trials are warranted.

[Effect of three-dimensional printing-assisted minimally invasive plate osteosynthesis on anti-malrotation for different types of tibial fractures].

OBJECTIVE: To compare the postoperative tibial malrotation between traditional minimally invasive plate osteosynthesis (MIPO) and three-dimensional printing-assisted MIPO (3D-MIPO) for different types of tibial fractures, and explore the change of these differences. METHODS: A prospective randomized controlled trial was conducted. The 120 patients with unilateral tibial fracture who met the selection criteria between January 2016 and October 2018 (40 patients in each of AO types A, B, and C) into the trial group (20 patients, 3D-MIPO) and the control group (20 patients, traditional MIPO) at ratio of 1∶1. There was no significant difference between the two groups (P>0.05) in gender, age, fracture site, and other general information. The bilateral tibial rotation angles were measured on the CT images within 1 week after operation, and the difference of tibial rotation angle between affected and unaffected sides was calculated. The tibial malrotation was defined when the difference exceeded 10°. The degree of tibial rotation and the incidence of malrotation between the two groups in different types of tibial fractures were compared. RESULTS: Postoperative infection occurred in 1 case, and improved after the dressing change and anti-inflammatory treatment. No complications such as loosening and displacement of internal fixation occurred. There was no significant difference in the difference of bilateral tibial rotation angles between the two groups in type A fractures after operation (t=0.559, P=0.580); while in types B and C fractures, the differences of bilateral tibial rotation angles in control group were significantly higher than those in trial group (P<0.05). There was no significant difference in distribution of internal or external rotation between the two groups in types A, B, and C fractures (P>0.05). No malrotation occurred in type A fractures, and there was no significant difference in the incidence of malrotation between the two groups in type B fractures (P=1.000). The incidence of malrotation in control group was significantly higher than that in trial group in type C fractures (P=0.044). CONCLUSION: 3D-MIPO has the same anti-malrotation effect as traditional MIPO for type A tibial fracture, but for types B and C tibial fractures, the anti-malrotation effect of 3D-MIPO is significantly better than that of traditional MIPO. The more complex the fracture type is, the more significant this advantage is.