RESUMO
Objective: To investigate the effect of sufentanil for spinal analgesia during cesarean section. Method: Eligible papers were systematically retrieved from PubMed, Embase, Ovid, and ScienceDirect. Two researchers independently extracted primary and secondary endpoints to compute relative risk and mean difference by using the random-effects model or the fixed-effects model, as appropriate. Publication bias was quantified and assessed using funnel plot and Egger's test. Result: A total of 8 publications with 503 pregnant women were included in this study for meta-analysis. Subarachnoid administration of sufentanil did not significantly reduce the onset time of sensory block and motor block. Nonetheless, subarachnoid administration of sufentanil significantly increased the incidence of postoperative skin pruritus (RR = 5.25, 95%CI: 1.90, 14.49, P < 0.001). Conclusion: Subarachnoid administration of sufentanil has no significant difference in the combined effect value of shortening the onset time of sensory block and motor block, prolonging the onset time of local anesthesia and the incidence of some adverse reactions (such as postoperative nausea, vomiting, hypotension, and tremors). However, the incidence of skin pruritus was significantly increased, and the difference was statistically significant. Because of this, the drug still needs to be used with caution in combination with the actual situation in clinical use.
Assuntos
Analgesia , Sufentanil , Cesárea/efeitos adversos , Feminino , Humanos , Dor , Gravidez , Prurido/induzido quimicamente , Ensaios Clínicos Controlados Aleatórios como Assunto , Sufentanil/efeitos adversosRESUMO
Retinal vein occlusion (RVO) refers to the occlusion of the central retinal vein or primary and secondary branches caused by multiple factors. Clinical treatments for it include intravitreal or systemic vasodilator application, local usage of steroids and NSAID (non-steroidal anti-inflammatory drugs), thrombolysis, hemodilution, retinal laser photocoagulation, vitrectomy with vascular sheath incision, chorioretinal venous anastomosis (CRVA), and so on. At present, most treatments are aimed at RVO complications, while chorioretinal vein anastomosis can fundamentally reflux retinal vein blood through the choroid by venous vascular remodeling. Reports on the treatment of retinal vein occlusion by chorioretinal anastomosis are numerous in various countries. As a treatment means, CRVA can drain the venous blood, skipping the thrombosis spot, thus partially relieving anatomical vascular occlusion to achieve a therapeutic purpose. In this study, CRVA is evaluated from the aspects of indications, implementation process, postoperative effect evaluation, complications, and combination with anti-VEGF treatment. Based on the development of laser technology and vitrectomy, we hope to further review this treatment and provide a new reference for the clinical treatment of RVO.
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We report the laser-diode pumped multi-gigahertz (GHz) self-mode-locked alexandrite femtosecond (fs) lasers for the first time, to the best of our knowledge. Using a simple linear cavity, stable mode-locked laser was achieved with a repetition rate of 3.6 GHz and a pulse width of 237 fs. Additionally, the second-harmonic mode-locked pulse was realized with a repetition rate of 7.5 GHz and a pulse width of 201 fs based on the Fabry-Perot effect generated in the laser cavity. It was observed that this laser possesses advantages of high repetition rate and short pulse width that enable the development of promising applications in modern ultrafast photonics.
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This paper describes a high pulse repetition frequency Nd:YAG twisted-mode laser that uses an RTP crystal as the electro-optic Q-switch. Stable single-longitudinal-mode laser beams at 1, 5, and 10 kHz were obtained with a linewidth less than 0.1 GHz. Under an incident pump power of 7.5 W and a PRF of 10 kHz, the maximum output power of the single-longitudinal-mode laser was 1.19 W. The corresponding conversion efficiency, single pulse energy and pulse peak power were 15.8%, 119 µJ, and 2.5 kW, respectively.
RESUMO
A compact laser diode pumped, actively Q-switched, and mode-locked Nd:YAG/PbWO(4) Raman laser is demonstrated. With the incident pump power of 9.11 W and pulse repetition frequency of 15 kHz, a maximum average output power of 1.003 W at 1178 nm was obtained and the corresponding conversion efficiency was 11%. A perfect stable mode-locking operation with the modulation depth of 100% was obtained and the corresponding mode-locking pulse width was less than 207 ps. The actively Q-switched and mode-locked Raman laser was theoretically analyzed and calculations were conducted using the fluctuation rate equation model.
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The compact LD end-pumped passively Q-switched c-cut Nd:YVO4/Cr4+:YAG self-Raman laser is realized, and its output performance is investigated in detail. The maximum average output power at 1178nm is 800mW with the pulse repetition frequency of 44kHz and pulse width of 2.6ns, and the first Stokes conversion efficiency is 10.1%. The outputs of fundamental and first Stokes laser are found to be linearly polarized along the diagonals of the rectangular cross section of the c-cut Nd:YVO4 crystal, and the polarization mode competition is observed in the outputs of fundamental and first Stokes laser.
RESUMO
Normalized space-dependent rate equations of passively Q-switched intracavity frequency-doubled Raman lasers are deduced for the first time. The normalized rate equations are solved numerically to investigate the influences of the normalized variables on the yellow laser performance. The LD end-pumped passively Q-switched Nd:YAG/SrWO(4)/KTP/Cr:YAG yellow Raman laser is realized, and the maximum yellow laser output power is 350 mW with the incident pump power of 5.9 W with Cr:YAG of 85% initial transmission. The theoretical analysis and optimization are taken out for the experiment, and the theoretical results are in accordance with the experimental ones.