Accurate non-intrusive residual bandwidth estimation in WMNs

The multi-access scheme of 802.11 wireless networks imposes difficulties in achieving predictable service quality in multi-hop networks. In such networks, the residual capacity of wireless links should be estimated for resource allocation services such as flow admission control. In this paper, we propose an accurate and non-intrusive method to estimate the residual bandwidth of an 802.11 link. Inputs from neighboring network activity measurements and from a basic collision detection mechanism are fed to the analytical model so that the proposed algorithm calculates the maximum allowable traffic level for this link. We evaluate the efficiency of the method via OPNET simulations, and show that the percent estimation error is significantly lower than two other prominent estimation methods, bounded only between 2.5-7.5%. We also demonstrate that flow admission control is successfully achieved in a realistic WMN scenario. Flow control through our proposed algorithm keeps the unsatisfied traffic demand bounded and at a negligibly low level, which is less than an order of magnitude of the other two methods

Erector spinae plane block vs interscalene brachial plexus block for postoperative analgesia management in patients who underwent shoulder arthroscopy

Background Interscalene brachial plexus block (ISB) is the gold standard method used for postoperative analgesia after arthroscopic shoulder surgery. Ultrasound guided erector spinae plane block (ESPB) is an interfascial plane block. The aim of this study is to compare the analgesic efficacy of ESPB and ISB after shoulder arthroscopy. The primary outcome is the comparison of the perioperative and postoperative opioid consumptions. Methods Sixty patients with ASA score I-II planned for arthroscopic shoulder surgery were included in the study. ESPB was planned in Group ESPB (n = 30), and ISB was planned in Group ISB (n = 30). Intravenous fentanyl patient-controlled analgesia was administered to both groups in the postoperative period. Intraoperative and postoperative opioid and analgesic consumption of both groups, side effects and complications related to opioid use, postoperative pain scores and rescue analgesic use were recorded in the first 48 h postoperatively. Results Pain scores were significantly higher in the ESPB group in the first 4 h postoperatively than in the ISB group (p < 0.05). The total fentanyl consumption and number of patients using rescue analgesics in the postoperative period were significantly higher in the ESPB group (p < 0.05). The incidence of nausea in the postoperative period was significantly higher in the ESPB group (p < 0.05). Conclusions In our study, it was seen that ISB provided more effective analgesia management compared to ESPB in patients underwent shoulder arthroscopy surgery

Regio- and stereo-chemical ring-opening reactions of the 2,3-epoxy alcohol derivative with nucleophiles: Explanation of the structures and C-2 selectivity supported by theoretical computations

The ring-opening reactions of (1aS,2S,6bR)-5-ethyl-2-hydroxyhexahydro-4H-oxireno[2,3-e]isoindole-4,6(5H)-dione were investigated under very mild and nonchelated conditions. C-2 selective ring-opening products were obtained with nucleophilic additions such as Cl-, Br- and N-3(-). The exact configuration of (3aS,4R,5R,6S,7aS)-5-chloro-2-ethyl-4,6-dihydroxyhexahydro-1H-isoindole-1,3(2H)-dione was determined by X-Ray diffraction analysis which was obtained from the reaction of epoxy alcohol with HCl . On the other hand, theoretical computations were carried out to explain the regioselectivity in the ring opening reaction of epoxy alcohols. The results showed that the ring-opening reaction of both epoxy alcohols proceeds in a kinetically controlled manner and regioselectivity occurs depending on the transition state. (c) 2022 Published by Elsevier B.V

A comparison of adductor canal block before and after thigh tourniquet during knee arthroscopy: A randomized, blinded study

Background: Adductor canal block (ACB) provides effective analgesia management after arthroscopic knee surgery. However, there is insufficient data about performing ACB before or after inflation of a thigh tourniquet. We aimed to investigate the efficacy of ACB when it is performed before and after thigh tourniquet and evaluate motor weakness. Methods: ACB was performed before the tourniquet inflation in the PreT group, it was performed after the inflation of the tourniquet in the PostT group. In the PO group, ACB was performed at the end of surgery after disinflation of the tourniquet. Results: There were no statistical differences between the groups in terms of demographic data. Opioid consumption showed no statistically significant differences (for total consumption; p = 0.5). The amount of rescue analgesia administered and patient satisfaction were also not significantly different between groups. There was no significant difference in terms of static and dynamic VAS scores between groups (for 24 hours; p = 0.3, p = 0.2 respectively). The incidence of motor block was higher in the PreT group (eight patients) than in the PostT group (no patients) and in the PO group (only one patient) (p = 0.005). Conclusions: Using a tourniquet before or after ACB may not result in any differences in terms of analgesia; however, applying a tourniquet immediately after ACB may lead to muscle weakness

Video yardımcılı torakal cerrahi sonrası postoperatif analjezi yönetimi için ultrasonografi rehberliğinde yapılan erektor spina plan bloğu ve torakal paravertebral blok etkinliği: Prospektif, randomize, kontrollü çalışma

Objective: Evaluation of the effectiveness of ultrasound (US)-guided erector spinae plane block (ESPB) and thoracic paravertebral block (TPVB) compared to no intervention control group for postoperative pain management in video assisted thoracic surgery (VATS) patients. Method: Three groups - Group ESPB, Group TPVB and the control group (n=30 per group) were included in this prospective, randomized, controlled study. The US-guided blocks were performed preoperatively in the ESPB and TPVB groups. Intravenous patient-controlled postoperative analgesia via fentanyl was administered in all of the patients. The patients were evaluated using visual analogue scale (VAS) scores, opioid consumption, and adverse events. Results: At all time intervals fentanyl consumption and VAS scores were significantly lower both in ESPB and TPVB groups compared to the control group (p<0.001). Block procedure time was significantly lower and success of one time puncture was higher in Group ESPB as compared with that in Group TPVB (p<0.001). Conclusion: ESPB and TPVB provide more effective analgesia compared to control group in patients who underwent video-assisted thoracic surgery. ESPB had a shorter procedural time and higher success of single-shot technique compared to TPVB.Amaç: Video yardımcılı torakal cerrahi yapılan hastalarda postoperatif analjezi yönetimi içinultrasonografi (US) eşliğinde yapılan erektor spina plan bloğu (ESPB) ve torakal paravertebralbloğun (TPVB) kontrol grubuna göre etkinliğinin değerlendirilmesi amaçlanmıştır.Yöntem: Bu çalışmaya her grup için 30 hasta olmak üzere toplam 90 hasta dahil edilmiştir.Çalışma 3 gruptan oluşmaktadır; Grup ESPB, Grup TPVB ve Kontrol Grubu. ESPB ve TPVB gruplarındaki hastalara preoperatif olarak US eşliğinde blok yapıldı. Tüm gruplardaki hastalara fentaniliçeren hasta kontrollü analjezi (HKA) uygulandı. Hastalar vizuel analog skala (VAS), opioid tüketimi ve yan etkiler kaydedilerek değerlendirildi.Bulgular: Tüm zaman aralıklarında fentanil tüketimi ve VAS Grup ESPB ve Grup TPVB de kontrolgrubuna göre anlamlı olarak daha düşüktü (p<0.001). Blok işlem süresi ESPB grubunda anlamlıolarak daha kısaydı ve iğne ile tek giriş başarısı ESPB grubunda TPVB grubuna göre anlamlı olarakdaha yüksekti (p<0.001).Sonuç: ESPB ve TPVB, video yardımcılı torakal cerrahi yapılan hastalarda kontrol grubuna göreetkili analjezi oluşturmaktadır. ESPB, TPVB’ye göre daha kısa işlem süresi ve tek iğne girişi ile dahayüksek başarı oranına sahiptir

Ultrasound guided rhomboid intercostal block provides effective pain control after video-assisted thoracoscopic surgery: A brief report of three cases

Dear editor;Rhomboid intercostal block (RIB) is a novel block and it may be used for several indications[1,2]. It may be performed for open thoracotomy [3], however more information is needed for otherthoracic procedures. Video-assisted thoracic surgery (VATS) has the advantages of reduced painover open thoracotomy. However patients may still feel moderate to severe pain after VATS [4].Herein, we report RIB in 3 patients for analgesia management after VATS. Written informedconsent for the procedure and future publishing were obtained from the patients