Midterm results of radiofrequency ablation with multiple heat cycles for incompetent saphenous veins.

OBJECTIVE: Recent reports suggest that the number of radiofrequency ablation (RFA) cycles impacts the depth of vein wall damage. This study evaluates the midterm occlusion rate after delivering increased energy during RFA of incompetent saphenous veins. METHODS: Between 2016 and 2019, consecutive patients who underwent RFA with multiple heat cycles were enrolled in the study. The exclusion criterion was previous treatment history for chronic venous disease. Duplex ultrasound data and medical records were reviewed retrospectively. RESULTS: This study enrolled 217 patients (345 veins). Follow-up examinations were performed for 65% of treated veins after 6 months, 31% after 12 months, and 26% after more than 24 months with a mean follow-up period of 23 ± 18.9 months. The numbers of great saphenous and small saphenous veins were 178 and 62, respectively. According to the Kaplan-Meier method, the occlusion rate of saphenous veins was 100% at 3 years and 95.4% at 5 years. Except for one case (0.3%) of endovenous heat-induced thrombosis class 2, no significant side effects were noted. CONCLUSIONS: Routine use of RFA with multiple heat cycles for incompetent saphenous veins exhibits good clinical outcomes considering midterm occlusion rate without an increase in side effects.

Prognosis of reflux of the below-knee great saphenous vein after surgical or endovenous treatment of reflux of the above-knee great saphenous vein.

OBJECTIVE: This study aimed to investigate the prognosis of preoperative reflux in the below-knee great saphenous vein (BK-GSV) after surgical or endovenous treatment of reflux of the above-knee GSV (AK-GSV) with concomitant stab avulsion of tributary varicosities and correlation between the results of preoperative duplex ultrasound (DUS) and postoperative reflux status of the BK-GSV. METHODS: From August 2015 to May 2018, there were 63 limbs (59 patients) with untreated primary varicose vein with reflux in the whole length of the GSV included in this study. The treatment methods were conventional surgery and radiofrequency ablation. Patients underwent DUS and assessment of Venous Clinical Severity Score (VCSS) and Aberdeen Varicose Vein Symptom Severity (AVVSS) score before treatment and at 6 and 12 months after treatment. RESULTS: Reflux in the BK-GSV persisted in 51% (32/63) of limbs at 6 months and 51% (18/35) at 12 months after treatment of reflux of the AK-GSV combined with stab avulsion of tributary varicosities. The reflux status of the BK-GSV after treatment was independent of diameter (P = .65 at 6 months and P = .68 at 12 months) and duration of reflux of the BK-GSV (P = .76 at 6 months and P = .95 at 12 months) on preoperative DUS. The percentage improvement in the VCSS and AVVSS score, respectively, was 46% and 58% in the group of competent BK-GSV and 54% and 80% in the group of incompetent BK-GSV at 6 months (P = .52 for VCSS; P = .28 for AVVSS score) and 95% and 90% in the group of competent BK-GSV and 87% and 92% in the group of incompetent BK-GSV at 12 months (P = .15 for VCSS; P = .84 for AVVSS score). CONCLUSIONS: Although preoperative reflux in the BK-GSV persists in half of limbs after treatment of reflux of the AK-GSV combined with stab avulsion of tributary varicosities, clinical results and quality of life improve regardless of reflux status of the BK-GSV. The postoperative reflux status of the BK-GSV is independent of diameter and duration of reflux of the BK-GSV on preoperative DUS.

The Effect of Saphenous Vein Ablation on Combined Segmental Popliteal Vein Reflux.

BACKGROUND: This study examined the role of superficial vein surgery in patients with combined superficial venous reflux and segmental popliteal vein reflux. METHODS: We retrospectively reviewed 42 limbs in 38 patients with combined superficial venous reflux and segmental popliteal vein reflux who underwent saphenous vein ablation between January 2014 and February 2017. Patients underwent outpatient follow-up duplex ultrasonography at 3, 6, and 12 months postoperatively. Resolution of deep vein reflux was defined as reversed blood flow in a popliteal segment for less than 1.0 second and a decrease in the reflux time of more than 20% of the preoperative reflux time. RESULTS: The mean follow-up period was 9 months (range, 3-23 months). Saphenous vein ablations were performed by stripping in 24 limbs and radiofrequency ablation in 18 limbs. Preoperative segmental popliteal vein reflux resolved in 21 of the 42 limbs (50%). CONCLUSION: This study demonstrated that superficial venous surgery corrected segmental popliteal vein reflux in 50% of limbs with combined superficial venous reflux and segmental popliteal vein reflux. Other prospective studies are necessary to elucidate the etiology of the non-reversible cases.

Effect of optogenetic manipulation of accumbal medium spiny neurons expressing dopamine D2 receptors in cocaine-induced behavioral sensitization.

Repetitive exposure to addictive drugs causes synaptic modification in the mesocorticolimbic dopamine (DA) system. Dopamine D1 receptors (D1R) or D2 receptors (D2R) expressed in the medium spiny neurons (MSNs) of the nucleus accumbens (NAc) play critical roles in the control of addictive behaviors. Optogenetic activation of D2R-expressing MSNs (D2R-MSNs) in the NAc previously demonstrated that these neurons play a key role in withdrawal-induced plasticity. Here, we examined the effect of optogenetic inhibition of D2R-MSNs in the NAc on cocaine-induced behavioral sensitization. Adeno-associated viral vectors encoding archaerhodopsin (ArchT) were delivered into the NAc of D2-Cre transgenic mice. Activation of ArchT produced photoinhibition of D2R-MSNs and caused disinhibition of neighboring MSNs in the NAc. However, such optogenetic silencing of D2R-MSNs in the NAc in vivo affected neither the initiation nor the expression of cocaine-induced behavioral sensitization. Similarly, photoinhibition of NAc D2R-MSNs in the NAc during the drug withdrawal period did not affect the expression of cocaine-induced behavioral sensitization. More detailed analysis of the effects of optogenetic activation of D2R-MSNs suggests that D2R-MSNs in the NAc exert important modulatory effects on neighboring MSN neurons, which may control the balanced output of NAc MSNs to control addictive behaviors.

Subcostal closure technique for prevention of postthoracotomy pain syndrome.

BACKGROUND: The purpose of this study was to evaluate the efficacy of our subcostal closure technique in prevention of postthoracotomy pain syndrome. METHODS: From July 2012 to March 2015, 29 patients in whom a lobectomy was indicated underwent a thoracotomy. The thoracotomy wounds were closed using a subcostal closure technique (subcostal closure group) and outcomes were compared with 31 patients who underwent video-assisted thoracoscopic surgery (thoracoscopy group). The duration of oral opioid consumption was evaluated from medical records, and postoperative pain was evaluated by telephone interview conducted by a trained nurse practitioner who was unaware of the patient's group. RESULTS: Pain scores were higher in the thoracoscopy group compared to the subcostal closure group, reaching statistical significance (Numeric Rating Scale 0.55 ± 0.948 in the subcostal closure group vs. 1.84 ± 1.614 in the thoracoscopy group; p < 0.001, Clinical Pain Scale 0.24 ± 0.435 in the subcostal closure group vs. 0.81 ± 0.703 in the thoracoscopy group; p < 0.001). The number of patients who consumed oral opioids for longer than 2 months after the operation was significantly greater in the thoracoscopy group than the subcostal closure group (6.9% in the subcostal closure group vs. 32.3% in the thoracoscopy group; p = 0.022). CONCLUSIONS: The subcostal closure technique is useful to prevent postthoracotomy pain syndrome.

High-performance triisopropylsilylethynyl pentacene transistors via spin coating with a crystallization-assisting layer.

The effects of spin speed and an amorphous fluoropolymer (CYTOP)-patterned substrate on the crystalline structures and device performance of triisopropylsilylethynyl pentacene (TIPS-PEN) organic field-effect transistors (OFETs) were investigated. The crystallinity of the TIPS-PEN film was enhanced by decreasing the spin speed, because slow evaporation of the solvent provided a sufficient time for the formation of thermodynamically stable crystalline structures. In addition, the adoption of a CYTOP-patterned substrate induced the three-dimensional (3D) growth of the TIPS-PEN crystals, because the patterned substrate confined the TIPS-PEN molecules and allowed sufficient time for the self-organization of TIPS-PEN. TIPS-PEN OFETs fabricated at a spin speed of 300 rpm with a CYTOP-patterned substrate showed a field-effect mobility of 0.131 cm(2) V(-1) s(-1), which is a remarkable improvement over previous spin-coated TIPS-PEN OFETs.

Multiwall carbon nanotube and poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) composite films for transistor and inverter devices.

Highly conductive multiwalled carbon nanotube (MWNT)/Poly(3,4-ethylenedioxythiophene) polymerized with poly(4-styrenesulfonate) (PEDOT:PSS) films were prepared by spin coating a mixture solution. The solution was prepared by dispersing MWNT in the PEDOT:PSS solution in water using ultrasonication without any oxidation process. The effect of the MWNT loading in the solution on the film properties such as surface roughness, work function, surface energy, optical transparency, and conductivity was studied. The conductivity of MWNT/PEDOT:PSS composite film was increased with higher MWNT loading and the high conductivity of MWNT/PEDOT:PSS films enabled them to be used as a source/drain electrode in organic thin film transistor (OTFT). The pentacene TFT with MWNT/PEDOT:PSS S/D electrode showed much higher performance with mobility about 0.2 cm²/(V s) and on/off ratio about 5 × 105 compared to that with PEDOT:PSS S/D electrode (∼0.05 cm²/(V s), 1 × 105). The complementary inverters exhibited excellent characteristics, including high gain value of about 30.

Photopatternable poly(4-styrene sulfonic acid)-wrapped MWNT thin-film source/drain electrodes for use in organic field-effect transistors.

We describe the cross-linking of poly(4-styrene-sulfonic acid) (PSS) by exposure to ultraviolet (UV) light (λ = 255 nm) under a vacuum. Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) showed that the photo-crosslinking of PSS resulted from coupling between radicals that were generated in the polymer chains by UV excitation. The photo-cross-linkable characteristics of PSS were employed to fabricate solution-processable, photopatternable, and conductive PSS-wrapped multiwalled carbon nanotube (MWNT) composite thin films by wrapping MWNTs with PSS in water. During photo-cross-linking, the work function of the PSS-wrapped MWNTs decreased from 4.83 to 4.53 eV following cleavage of a significant number of sulfonic acid groups. Despite the decreased work function of the PSS-wrapped MWNTs, the photopatterned PSS-wrapped MWNTs produced good source/drain electrodes for OFETs, yielding a mobility (0.134 ± 0.056 cm²/(V s)) for the TIPS-PEN field-effect transistors fabricated using PSS-wrapped MWNTs as source/drain electrodes that was higher than the mobility of gold-based transistors (0.011 ± 0.004 cm²/(V s)).

Solution-processed flexible ZnO transparent thin-film transistors with a polymer gate dielectric fabricated by microwave heating.

We report the development of solution-processed zinc oxide (ZnO) transparent thin-film transistors (TFTs) with a poly(2-hydroxyethyl methacrylate) (PHEMA) gate dielectric on a plastic substrate. The ZnO nanorod film active layer, prepared by microwave heating, showed a highly uniform and densely packed array of large crystal size (58 nm) in the [002] direction of ZnO nanorods on the plasma-treated PHEMA. The flexible ZnO TFTs with the plasma-treated PHEMA gate dielectric exhibited an electron mobility of 1.1 cm(2) V(-1) s(-1), which was higher by a factor of approximately 8.5 than that of ZnO TFTs based on the bare PHEMA gate dielectric.

Photopatternable source/drain electrodes using multiwalled carbon nanotube/polymer nanocomposites for organic field-effect transistors.

We fabricated photopatternable and conductive polymer/multiwalled carbon nanotube (MWNT) composites by dispersing MWNTs with poly(4-styrenesulfonic acid) (PSS) and poly(acrylic acid) (PAA) in water. PAA enables photo-cross-linking in the composite by adding ammonium dichromate, and PSS assists the dispersion of MWNTs in the composites, leading to higher conductivity. Composite films of PAA/PSS-MWNTs were characterized by conductivities of 1.4-210 S/cm and a work function of 4.46 eV, which could be increased to 4.76 eV during UV photo-cross-linking. By using PAA/PSS-MWNT composites as source/drain electrodes, 6,13-bis(triisopropylsilylethynyl)pentacene field-effect transistors (FET) exhibited a field-effect mobility of 0.101 +/- 0.034 cm(2)/(V s), which is 9 times higher than that of FETs fabricated with gold as source/drain electrodes (0.012 +/- 0.003 cm(2)/(V s)).