ARTERIOVENOUS MALFORMATIONS OF THE BRAIN: ACHIEVEMENTS, ANALYSIS OF DIAGNOSIS AND TACTICS OF SURGICAL TREATMENT IN THE CONDITIONS OF THE REPUBLICAN RESEARCH CENTER OF EMERGENCY MEDICAL CARE (20-YEAR OF THE CLINIC EXPERIENCE)

Aim. To assess the results of the activities of the neurosurgical service of the Republican Research Center of Emergency Medicine (RRCEM) over a twenty-year period of operation with an analysis of the results of neurosurgical care for patients with arteriovenous malformations of the brain (AVM). Material and Methods. The analysis was carried out of 54 patients examined and operated on for AVM, in the period from 2001 to 2020, who were treated at the Department of Adult Neurosurgery of the RRCEM. Results. The basis of our principle of a differentiated surgical approach in the treatment of AVM is the determination of the AVM grading according to the Spetzler-Martin and Lawton-Young scales. Limiting only microsurgical AVM resection is advisable for AVMs – I and II grades according to the Spetzler-Martin and Lawton-Young scales. For patients with high grades of AVMs – grade III and more, it is more expedient to use a combined technique, and with deeply located AVMs, endovascular embolization.

Study on the Absorption Characteristics and Laser Damage Properties of Fused Silica Optics under Flexible Polishing and Shallow DCE Process

The enhancement of laser damage resistance of fused silica optics was a hotspot in scientific research. At present, a variety of modern processes have been produced to improve the laser induced damage threshold (LIDT) of fused silica optics. They included pre-treatment processes represented by flexible computer controlled optical surfacing (CCOS), magnetorheological finishing (MRF), ion beam finishing (IBF), and post-treatment processes represented by dynamic chemical etching (DCE). These have achieved remarkable results. However, there are still some problems that need to be solved urgently, such as excessive material removal, surface accuracy fluctuation in the DCE process, and the pollution in MRF process, etc. In view of above problems, an MRF, CCOS, IBF and shallow DCE combined technique was used to process fused silica optics. The surface morphology could be greatly controlled and chemical etching depth was reduced, while the LIDT increased steadily. After processing by this combined technique, the LIDT increased to 12.1 J/cm2 and the laser damage resistance properties of fused silica were significantly enhanced. In general, the MRF, IBF, CCOS and shallow DCE combined technique brought much help to the enhancement of laser damage resistance of fused silica, and could be used as a process route in the manufacturing process of fused silica.

Modelling the Accommodation Preferences of Tourists by Combining Fuzzy-AHP and GIS Methods

Finding the place of accommodation is one of the most crucial issues during a journey. This study aims to support the decision-making of tourists for choosing the optimal accommodation by combining fuzzy analytic hierarchy process (FAHP) and geographic information system (GIS) techniques. The adopted criteria are the cost per room, the distance from the center, the level of security, the place rating, and the availability of free cancellation and breakfast. Due to some uncertainty and diversity of criteria, the FAHP approach is applied to consolidate tourists’ decisions by applying criteria weighting, while the GIS is used to overlay the weighted criteria and to visualize the ranked places of accommodation on a map. The combined technique is applied on a case study in Budapest City, where the analysis is conducted on 364 places of accommodation. The results show that half of the places are recommended for tourists, and more than fifth of the accommodations are highly recommended. Furthermore, it can be concluded that the cost per room was the highest influential criterion with 0.233 importance weight, followed by the security level with 0.205. The lowest factor affecting the choice of accommodation was the free cancellation service. It was demonstrated that the rating weight importance was 0.182, while the breakfast and the distance from the center had approximately the same importance. As a recommendation, some improvements on the accommodation, such as decreasing the cost per room, enhancing the services, or developing the quality of the places, would increase their attractiveness for tourists.

Anesthesia for knee arthroscopy: which nerves should be blocked?

Nowadays knee arthroscopy is the most common orthopedic procedure. It is used to diagnose and treat various pathological conditions. Usually knee arthroscopy can be performed using spinal anesthesia. The article presents a successful experience of using a combined technique, which consist in a unilateral subarachnoid anesthesia with additional adductor canal block and blocks of the articular branches of the sciatic and obturator nerves.

On the Decrease in Transformation Stress in a Bicrystal Cu-Al-Mn Shape-Memory Alloy during Cyclic Compressive Deformation

The evolution of the inhomogeneous distribution of the transformation stress (σs) and strain fields with an increasing number of cycles in two differently orientated grains is investigated for the first time using a combined technique of digital image correlation and data-driven identification. The theoretical transformation strains (εT) of these two grains with crystal orientations [5 3 26]β and [6 5 11]β along the loading direction are 10.1% and 7.1%, respectively. The grain with lower εT has a higher σs initially and a faster decrease in σs compared with the grain with higher εT. The results show that the grains with higher σs might trigger more dislocations during the martensite transformation, and thus result in greater residual strain and a larger decrease in σs during subsequent cycles. Grain boundary kinking in bicrystal induces an additional decrease in transformation stress. We conclude that a grain with crystal orientation that has high transformation strain and low transformation stress (with respect to loading direction) will exhibit stable transformation stress, and thus lead to higher functional performance in Cu-based shape memory alloys.

A Combined Technology to Protect the Anatomic Integrity of Distal Urethral Sphincter Complex in Radical Prostatectomy Improves Early Urinary Continence Recovery Without Sacrifice of Oncological Outcomes

PurposeOur primary aim was to present a combined technique to protect the anatomic integrity of distal urethral sphincter complex (DUSC) during minimally invasive radical prostatectomy (RP) and discuss its impact on urinary continence (UC) recovery. The second aim was to define the learning curve of the combined technique.MethodsWe conducted a non-randomized retrospective study. There were 314 consecutive patients who received RP by the same urologist surgeon with more than 2,000 prior cases in Shanghai Ruijin Hospital between March 2017 and April 2020. Included in this study were 263 patients with clinical T1–T2 stage. We modified a combined RP (Comb-RP) technique including endopelvic fascia no-incising technique, dorsal venous complex (DVC) no-ligation technique, intrafascial dissection technique, and anterior reconstruction technique so as to preserve the anatomic integrity of DUSC. The patients were assigned to two groups: a Comb-RP group and a conventional RP (Conv-RP) group. Continence rates were assessed every 3 months after removal of the catheter. UC was defined as 0 pad per day. Peri-operative variables of the patient including operation time, estimated blood lost (EBL), positive surgical margin (PSM), and postoperative complications were also collected. Scatter-graphs of learning curves were drawn using locally weighted scatterplot smoothing (LOWESS).ResultsRP was accomplished smoothly in all 263 cases. The pad-free UC rates in Conv-RP group and Comb-RP group were 17.3 vs. 27.8% (P = 0.048) at the removal of the catheter, 35.8 vs. 50.0% (P = 0.027) at 1 month, 60.5 vs. 76.1% (P = 0.012) at 3 months, 87.7 vs. 96.5% (P = 0.022) at 6 months, and 94.7 vs. 97.7% (P = 0.343) at 12 months. Kaplan–Meier analysis showed significantly higher and faster continence recovery in the Comb-RP group (mean 4.9 vs. 2.6 months, Log Rank P = 0.001). There was no significant difference in PSM rate between the Comb-RP and Conv-RP group (31.1 vs. 31.2%, P =0.986). The learning curves of peri-operative variables, oncological and functional outcomes achieved the lowest point or plateau at the 20th–60th cases.ConclusionsThe anatomic integrity and intact pelvic floor interplay of DUSC is important for its function. Our combined technique was a safe and feasible technique for improving early UC in RP with no significantly increased PSM rate and no significant difference in long-term UC.

Comparison of aspiration versus combined technique as first-line approach in terminal internal carotid artery occlusion: a multicenter experience

BackgroundThere is no consensus on the most effective endovascular technique to use in patients with acute ischemic stroke due to terminal internal carotid artery (ICA) occlusion. The aim of this study was to compare safety and efficacy of the aspiration technique (AT) and combined technique (CT) as first-line approach in terminal ICA occlusions.MethodsWe performed a retrospective analysis of prospectively collected databases from seven Italian stroke centers. Patients were divided into two subgroups according to the first-line approach: AT group or CT group. We followed the STROBE guidelines for cohort studies. We used Chi-square test, one-way and multivariate ANOVA analysis, together with contrast analysis and post hoc tests, logistic regression and Pearson’s bivariate correlation for the statistical analyses.ResultsBetween January 2018 and August 2020, 353 patients were treated for a terminal ICA occlusion, with either AT or CT. CT was associated with a higher Thrombolysis in Cerebral Infarction (TICI) 2B-3 after the first pass (51.0% vs 26.9%) and at the end of the procedure (84% vs 73.3%) and with an improved clinical outcome at discharge (modified Rankin Scale (mRs) 0–2 of 47.8% vs 34.0%) and at 3 months’ follow-up (mRs 0–2 of 56.5% vs 38.9%) compared with AT.ConclusionThrombectomy of terminal ICA occlusions obtained using CT as first-line approach demonstrated better technical and functional outcomes in comparison with AT.

Efficient Memory-based Multiplier Technique for SWL DSP Systems

The DSP systems usually deal with a lot of multiplications as it is dealt with many discrete signals. The combinational circuits consume a lot of power as there are many intermediate blocks (i.e., usually full adders & and gates). The combinational circuits take more area and the delay is also more. Usually there is a tradeoff between area and delay. To make the multiplier more efficient we usually prefer memory-based multiplier. Different types of techniques are there in memory-based multipliers like the APC (anti-symmetric product coding), OMS (odd multiple storage) etc. In these techniques LUT based storage is used. The multiplied products are stored efficiently based on the technique used to store the data. To optimize the memory required we combine the APC and OMS technique for better storage and retrieval of data. In this project we show how combined technique increases the performance of multiplier. The suggested combined technique reduces the size of the LUT to one-fourth that of a standard LUT. It is demonstrated that the proposed LUT architecture for tiny input sizes can be used to execute high-precision multiplication with input operand decomposition in an efficient manner.

First clinical experience of a new surgical technique including correction of bony alignment of first foot ray combined with reconstruction of muscle balance in case of adolescent hallux valgus

BACKGROUND: Hallux valgus deformity of the big toe in adolescents accounts for 22%44% of all relevant cases. Despite a relatively large number of surgical treatment methods proposed to correct this deformity, treatment results are not always satisfactory. The problem of imbalance between the external traction of the abductor hallucis muscle and the contracted adductor muscle in hallux valgus remains controversial and is not covered in the literature. AIM: This study aimed to examine the results of hallux valgus deformity treatment, following the suggested combined technique. MATERIALS AND METHODS: Eight teenage patients (10 feet), aged 15 years on average, were assessed. Patients were undergoing treatment in the department of pediatric orthopedics of the Dana Hospital, Tel Aviv, within the period from 2015 to 2019. The average postoperative observation period was 30 months. This study suggested a new combined technique, including (1) modified oblique Chevron osteotomy with a V-shaped cut in the distal aspect of the first metatarsal with the dorsal wedge excision performed at the apex of its angulation, (2) valgus osteotomy of the medial cuneiform bone with the insertion of the V-shaped bone allograft, and (3) transfer of the dorsal portion of the pre-split tendon of abductor hallucis muscle to the base of the triangular medial capsular flap of the first metatarsophalangeal joint (MPJ). The tendon received optimal tension to restore the muscular balance. RESULTS: This surgical technique provided safe and stable correction of the hallux valgus deformity, restored muscular balance, avoided movement restriction of the first MPJ, and restored the function and strength of the abductor halluces muscle that prevented the recurrence of the deformity. The number of good and excellent results was much greater than those in published reports. CONCLUSIONS: Despite a relatively small group of patients, the suggested technique has shown improvements in hallux valgus deformity in adolescents.