Lower Block Research Articles

Application of Intelligent Analysis Technology of Football Video Based on Online Target Tracking Algorithm of Motion Characteristics in Football Training.

Because the scene of football video is fixed and simple, the events in football video, such as shooting and offside , also have clear semantics. At the same time, they have sufficient domain knowledge and have broad application prospects. The research framework of sports video intelligence analysis is usually regarded as a three-level framework, namely, the low-level feature layer, the middle-level key primitive generation layer, and the high-level event analysis layer. A MF_O2T (Moving Feature Online Target Tracking) algorithm is proposed. First, based on the marked first frame image, this algorithm extracts a set of standardized local images from the target areas of visible and infrared images as target convolution filters, removes the main color of the stadium by using HSV color space nonuniform quantization algorithm, and extracts the histogram of the main color of players in upper and lower blocks. Experimental results show that the algorithm designed in this paper has strong robustness, can better adapt to player tracking in different scenes of football video, and meets the real-time requirements of football training.

Interaction Mechanism of the Upper and Lower Main Roofs with Different Properties in Close Coal Seams: A Case Study

Close-distance coal seams are widely distributed in China, and the mining of overlying coal seams leads to floor damage. To grasp the properties and the fracture spans of the damaged main roof in the underlying coal seam, combining the calculation of the floor damage depth with rock damage theory and the formulas for calculating the first and periodic weighting intervals of the damaged main roof and the instability conditions of the damaged key blocks are obtained. Three interaction stability mechanics models are proposed for key blocks with different properties of the upper and lower main roof, and the instability conditions of the lower damaged key blocks are obtained when the fracture lines overlap. When combined with a specific example, the field monitoring verified the calculation results. The research results are as follows: (1) The first and periodic weighting intervals, horizontal thrust between blocks, and critical load of instability of the damaged main roof are significantly reduced. Still, there are differences in its reduction under different loads, rotation angles, and lumpiness. (2) When the fracture lines of the upper and lower main roofs overlap, the stability of the damaged key blocks is the lowest. There are three linkage stability regions in the critical load curves of the two key blocks. (3) In this case, the damage equivalent of the main roof is 0.397, which belongs to the local damage type. Its first and periodic weighting intervals are 40 m and 16 m, which is 22% and 24% less than when there is no damage. (4) A supporting load of 0.489 MPa is required to maintain the stability of the upper key block, and the lower damaged key block is prone to rotary and sliding instability during the first and periodic weighting, respectively. Thus, the supports need to bear a total of 0.988 MPa and 0.761 MPa to maintain the stability of the two key blocks simultaneously. The ground pressure data monitored on-site is in accord with the calculation results.

Effects of waveform shape and electrode material on KiloHertz frequency alternating current block of mammalian peripheral nerve

ObjectivesKiloHertz frequency alternating current waveforms produce conduction block in peripheral nerves. It is not clearly known how the waveform shape affects block outcomes, and if waveform effects are frequency dependent. We determined the effects of waveform shape using two types of electrodes.Materials and methodsAcute in-vivo experiments were performed on 12 rats. Bipolar electrodes were used to electrically block motor nerve impulses in the sciatic nerve, as measured using force output from the gastrocnemius muscle. Three blocking waveforms were delivered (sinusoidal, square and triangular) at 6 frequencies (10–60 kHz). Bare platinum electrodes were compared with carbon black coated electrodes. We determined the minimum amplitude that could completely block motor nerve conduction (block threshold), and measured properties of the onset response, which is a transient period of nerve activation at the start of block. In-vivo results were compared with computational modeling conducted using the NEURON simulation environment using a nerve membrane model modified for stimulation in the kilohertz frequency range.ResultsFor the majority of parameters, in-vivo testing and simulations showed similar results: Block thresholds increased linearly with frequency for all three waveforms. Block thresholds were significantly different between waveforms; lowest for the square waveform and highest for triangular waveform. When converted to charge per cycle, square waveforms required the maximum charge per phase, and triangular waveforms the least. Onset parameters were affected by blocking frequency but not by waveform shape. Electrode comparisons were performed only in-vivo. Electrodes with carbon black coatings gave significantly lower block thresholds and reduced onset responses across all blocking frequencies. For 10 and 20 kHz, carbon black coating significantly reduced the charge required for nerve block.ConclusionsWe conclude that both sinusoidal and square waveforms at frequencies of 20 kHz or higher would be optimal. Future investigation of carbon black or other high charge capacity electrodes may be useful in achieving block with lower BTs and onsets. These findings will be of importance for designing clinical nerve block systems.

Does the Firm with Well-Educational Level of Board Members Have Good Corporate Governance?

This study examined the degree to which the educational level of directors affects corporate governance and firm value in firms. From the results, it has been found that the educational levels of directors are negatively related to corporate governance performance. On the other hand, firms with higher-educated directors have lower block shareholders’ holdings, which implies that the ownership right is not concentrated and block shareholders cannot effectively monitor the operation of the firm to avoid agency problems. Furthermore, a firm with higher educational levels of directors and stronger governance mechanisms is more significant to raise the firm value.

Comparison of efficacy and post injection parasthesia between articaine and lidocaine in local anesthesia for inferior alveolar nerve block

Puepose: Considering the high failure rate of using lidocaine in the lower jawbone block and the recommendation of some researchers regarding the use of articaine, and considering the contradictions and the lack of adequate and reliable evidence for comparing these two drugs, we found a study on comparing the effects and side effects of these two anesthesia. Methods: In a double-blind, randomized controlled trial, the effect and side effects of articaine 4% and lidocaine 2% with epinephrine 1 in 100000 units were compared in lower Jaw nerve block. 110 patients with molar tooth extraction were entered our study and divided into two groups of 55 subjects. Patients in case group received 4% articaine anesthesia in lower jaw block and Patients in control group received 2% lidocaine anesthesia in lower jaw block. The onset of the effect of anesthetics, the success rate of inducing complete anesthesia+, duration of anesthesia, patient's pain during surgery, and anesthetic stability (paresthesia) after 24 hours and one week were investigated in these two groups.

Characterization of Pennsylvanian Paleosols in Indiana with a Special Reference to Rare Earths (REE) and Lithium

This study characterizes Pennsylvanian paleosols from coal-bearing strata in Indiana, with the main emphasis on the abundance and distribution on rare earths (REE) and lithium (Li). Eleven locations in southwest Indiana were selected for this study, targeting paleosols of both the Carbondale Group and the Raccoon Creek Group. Most paleosols were directly underlying coal beds. Lithologically, paleosols range from grey mudstones to greenish-gray claystones and occasional siltstones. In the Carbondale Group, the thickest paleosol horizons occur under the Danville and the Houchin Creek Coal Members, with their thickness reaching close to 10 feet. In the Raccoon Creek Group, the paleosol under the Wise Ridge Coal appears to be thickest (4.6 to 11.4 feet) and best developed. Total REE content in paleosol samples ranges from 138.8 ppm to 728.55 ppm, with an average range of 208.3 ppm (Colchester paleosol) to 342.9 ppm in the paleosol under the Upper Block Coal. Light REE dominate over heavy REE, and the variation in the light REE is responsible for the largest variations of the total REE. The largest amount of the heavy REE (61 ppm) occurs in the paleosol under the Lower Block Coal, whereas the paleosol under the Upper Block Coal has the largest variation in the heavy REE content (49 to 148 ppm). REE patterns for paleosol samples show very weak to no fractionation among light, medium, and heavy REE, with no major anomalies present. The majority of paleosols have REE values that are roughly representative of the upper continental crust. Only some paleosols are slightly enriched and these are paleosol samples under the Danville Coal and the Upper Block Coal. Lithium content in the paleosol samples shows a variation from 21 ppm to 530 ppm. On average, the Wise Ridge Coal is richest in Li (249.3 ppm), followed by Viking B Coal (190.8 ppm). The coals of the Brazil and Staunton Formations have higher Li content than the younger coals. Although this study has not uncovered large concentrations of REE or lithium, the wide range of concentrations and potential ease of their extraction from these clay-rich rocks imply that the paleosols deserve further examination, and the current study can be used as a screening guide for more focused investigation.

Development of a Computational Fluid Dynamics (CFD) Numerical Approach of Thermoelectric Module for Power Generation

The recent innovations in thermoelectric generating materials have led to exceptional technologies that generate power from excess and lost heat. These technologies have proven to be of significant environmental and economic importance, especially with global warming issues and escalating fuel prices. This study developed a computational fluid dynamics (CFD) model for a thermoelectric generator (TEG) consisting of five TEG modules embedded between two aluminum blocks. The upper block collects solar energy and heats the hot side of the modules. The lower block has an internal M-shaped water channel to cool the cold side of the modules. The model predictions were compared with the authors’ previously published experimental results to assess its validity and reliability. A parametric study was conducted to investigate the effects of various solar collector block thicknesses and different water flow velocities on the TEG-generated voltage and efficiency. The results show excellent agreement between the model predictions and the experimental data. Moreover, the parametric study revealed a slight inverse relationship between the thickness of the solar-collecting mass, the efficiency of the system, and an increase in the heat flux. However, the relationship was proportional to the velocity of water flow.

A Height-Based Dosing Algorithm of Bupivacaine in Spinal Anesthesia for Decreasing Maternal Hypotension in Cesarean Section Without Prophylactic Fluid Preloading and Vasopressors: A Randomized-Controlled Non-Inferiority Trial.

BackgroundThere is a high incidence of maternal hypotension in spinal anesthesia for cesarean section. The aim of the study is to investigate whether there is a height-based dosing algorithm of bupivacaine that provides adequate anesthesia with less maternal hypotension.MethodsThere were 2 groups of 280 parturients who did not receive prophylactic fluid preloading: Test and Conventional group. In Test group, a height based dosing algorithm was used to confirm the dose of bupivacaine in parturients without prophylactic vasopressors. In the Conventional group, a constant dose of bupivacaine was used. The complications and quality of anesthesia were evaluated.ResultsIn the Conventional group, the shorter participants had higher incidence of hypotension, faster sensory block time, and more participants with complete motor block (p = 0.030, 2.957 × 10−14, and 0.012). In the Test group, the incidence of hypotension, sensory block time, and number of participants with complete motor block did not change with height (p = 0.199, 0.617, and 0.209). The height-based dosing algorithm of bupivacaine decreased the incidence of hypotension (p = 0.004), induced lower sensory block level and less degree of motor block (p = 3.513 × 10−7 and 5.711 × 10−11). The quality of analgesia, quality of muscle relaxation, and degree of intraoperative comfort were similar in both groups (p = 0.065, 0.498, and 0.483).ConclusionsThe height influences the dose of bupivacaine in spinal anesthesia; without prophylactic fluid pre-loading and vasopressors, the height-based dosing algorithm of bupivacaine is suitable, and meets the cesarean section' requirement with less maternal hypotension.Clinical Trial Registrationwww.ClinicalTrials.gov, identifier: NCT03497364.

Partially pivoted ACA based acceleration of the energetic BEM for time-domain acoustic and elastic waves exterior problems

We consider acoustic and elastic wave propagation problems in 2D unbounded domains, reformulated in terms of space-time Boundary Integral Equations (BIEs). For their numerical solution, we employ a weak formulation related to the energy of the system and we discretize the weak problems by a Galerkin-type Boundary Element Method (BEM): this approach, called Energetic BEM, has revealed accurate and stable even on large time intervals of analysis. In particular, it results that, when standard Lagrangian basis functions are considered, the BEM matrices have Toeplitz lower triangular block structure, where blocks for growing time become fully populated; hence the overall memory cost of the energetic BEM is O(M2N), M and N being the number of the space degrees of freedom and the total number of performed time steps, respectively. This drawback prevents the application of such method to large scale problems. As a possible remedy, we propose a fast technique based on the Adaptive Cross Approximation (ACA). The core of this procedure is the approximation of sufficiently large time blocks of the energetic BEM matrix through the partially pivoted ACA algorithm, which allows to compute only few of the original entries. This leads to reduced assembly time, which for the energetic BEM is generally relevant, coupled with reduced memory storage requirements. Additionally, the consequent acceleration of the matrix/vector multiplication together with a marching on time procedure, leads to remarkable reduction of the computational solution time. The effectiveness of the proposed method is theoretically proved and several numerical results are presented and discussed.

Gaudin models and multipoint conformal blocks III: comb channel coordinates and OPE factorisation

We continue the exploration of multipoint scalar comb channel blocks for conformal field theories in 3D and 4D. The central goal here is to construct novel comb channel cross ratios that are well adapted to perform projections onto all intermediate primary fields. More concretely, our new set of cross ratios includes three for each intermediate mixed symmetry tensor exchange. These variables are designed such that the associated power series expansion coincides with the sum over descendants. The leading term of this expansion is argued to factorise into a product of lower point blocks. We establish this remarkable factorisation property by studying the limiting behaviour of the Gaudin Hamiltonians that are used to characterise multipoint conformal blocks. For six points we can map the eigenvalue equations for the limiting Gaudin differential operators to Casimir equations of spinning four-point blocks.

Pediatric lower limb peripheral nerve blocks: Indications, effectiveness, and the incidence of adverse events.

While the proportion of pediatric anesthetics with regional anesthesia in pediatric patients has steadily increased, there are only a few series that describe the use of lower limb peripheral nerve blocks in children. Our aim was to describe the indications, anesthetic approach, and complications associated with lower limb blocks in children undergoing orthopedic surgery in a center with a large caseload of complex patients. In a retrospective analysis of prospectively collected data, we reviewed children who had a peripheral nerve block for orthopedic surgery placed between January 2016 and January 2021 at the Royal Children's Hospital Melbourne. Block data were sourced from the electronic medical record and departmental regional anesthesia database. Data collected included demographics, the site of catheter placement and technique of nerve block, presence of sensory/motor blockade, the use of perioperative opioids, and any complications related to peripheral nerve block. A total of 1438 blocks were performed in 1058 patients. Four patients had clinical features of perioperative neurological injury giving an incidence of 3 per 1000 blocks (95% CI 1.1-8:1000). Only one patient had a sensory deficit persisting longer than 6months for an incidence of 0.8 per 1000 blocks (95% CI 0.1-5:1000). All four peripheral nerve injury followed tibial osteotomy for lengthening procedures or correction of tibial torsion. The etiology of the injury could not be determined despite imaging and surgical exploration and the contribution of popliteal sciatic nerve block to the subsequent PNI could not be confirmed. There were no cases of local anesthetic systemic toxicity. An increased risk of perioperative peripheral nerve injury is associated with pediatric tibial osteotomy for congenital deformity. While popliteal sciatic nerve block was not directly implicated in the nerve injury the presence of a prolonged sensory block can delay early recognition and treatment of peripheral nerve injury.

A Practical Guide to Lower Extremity Nerve Blocks for the Sports Medicine Surgeon

Background: Peripheral nerve blocks (PNBs) are vital in the administration of surgical analgesia and have grown in popularity for use in lower extremity arthroscopic procedures because of their capacity to safely and effectively control pain. The number and specificity of PNBs, however, have made choosing the best option for a procedure nebulous for orthopaedic surgeons. Purpose: To present a narrative literature review of the PNBs available for arthroscopic hip and knee procedures that is adapted to an audience of orthopaedic surgeons. Study Design: Narrative literature review. Methods: A combination of the names of various lower extremity PNBs AND “hip arthroscopy” OR “knee arthroscopy” was used to search the English medical literature including PubMed, Cochrane Library, ScienceDirect, Embase, and Scopus. Placement technique, specificity of blockade, efficacy, and complications were assessed. Searches were performed through May 2, 2021. Results: A total of 157 studies were included in this review of lower extremity PNBs. Femoral nerve, lumbar plexus, sciatic nerve, and fascia iliaca compartment blocks were most commonly used in arthroscopic hip surgery, while femoral nerve, 3-in-1, and adductor canal blocks were preferred for arthroscopic knee surgery. Each block demonstrated a significant benefit (P > .05) in ≥1 of the following outcomes: intraoperative morphine, pain scores, nausea, and/or opioid consumption. Combination blocks including the lateral femoral cutaneous nerve block, obturator nerve block, quadratus lumborum block, and L1 and L2 paravertebral block have also been described. Complication rates ranged from 0% to 4.8% in those administered with ultrasound guidance. The most commonly reported complications included muscular weakness, postoperative falls, neuropathy, intravascular and intraneural injections, and hematomas. Conclusion: When administered properly, PNBs were a safe and effective adjuvant method of pain control with a significant potential to limit postoperative narcotic use. While blockade choice varies by surgeon preference and procedure, all PNBs should be administered with ultrasound guidance, and vigilant protocols for the risk of postoperative falls should be exercised in patients who receive them.

Programmed Intermittent Epidural Bolus in Comparison with Continuous Epidural Infusion for Uterine Contraction Pain Relief After Cesarean Section: A Randomized, Double-Blind Clinical Trial.

PurposeProgrammed intermittent epidural bolus (PIEB) was reported to provide superior maintenance of labour analgesia with better pain relief and less motor block than continuous epidural infusion (CEI). Whether this is also evident for uterine contraction pain relief after cesarean section remains unknown.Patients and MethodsParturients scheduled for cesarean section were recruited for the study. At the end of the surgery, after a similar epidural loading dose given, patients received either PIEB (6 mL·h−1) or CEI (6 mL·h−1) of 0.1% ropivacaine. The primary outcome was the uterine contraction pain assessed with visual analog scale (VAS-U) at the postoperative 36 h. Secondary outcomes included incision pain at the rest (VAS-R) and in the movement-evoked (VAS-P), and lower extremity motor block (defined as Bromage score > 0). The whole profile of VAS scores between groups was analyzed using linear mixed model. When significant differences were found, the pairwise comparison was done with the Mann Whitney U-test followed by Bonferroni correction.ResultsOne hundred and twenty parturients were studied (PIEB, 60; CEI, 60). VAS-U at the postoperative 36 h in the PIEB group was lower than in the CEI group (Bonferroni-adjusted P < 0.01). The linear mixed model indicated that VAS-U, VAS-R and VAS-P were lower in the PIEB group compared with the CEI group (all P < 0.01). Motor block was higher in the CEI group than in the PIEB group during the study period except 2 h (all P < 0.05). No differences of adverse events such as hypotension and urinary retention were observed between the two groups.ConclusionProgrammed intermittent epidural bolus provides more effective uterine contraction and incision pain relief and less motor block after cesarean section than continuous epidural infusion without an increased risk of urinary retention and blood pressure instability.

Evaluation and Analysis of Fellow Learning and Education Curriculum in a Regional Anesthesiology and Acute Pain Medicine Fellowship: A Prospective, Observational Pilot Study.

Since 2017, several regional anesthesiology and acute pain medicine fellowship programs throughout the country have developed various educational didactic curriculums to address the core medical knowledge requirements as set by the Accreditation Council for Graduate Medical Education. Given the paucity of existing literature regarding the medical knowledge acquisition of regional anesthesiology and acute pain medicine fellows, this study aimed to determine how quickly these fellows learn during their fellowship year, with a secondary aim of analyzing a new educational didactic curriculum in its goal of delivering the required medical knowledge. An 89-question, multiple-choice examination was administered to the 2020-2021 regional anesthesiology and acute pain medicine fellows at the University of Pittsburgh Medical Center during orientation and again at 4 months and 8 months into the fellowship. A secondary analysis of anonymous deidentified answers was completed. Fellows averaged 64%, 74%, and 79% correct responses on the orientation, 4-month, and 8-month exams, respectively. An analysis of the orientation exam revealed that the most commonly incorrect answers stemmed from topics including lower extremity nerve blocks, truncal blocks, and neuraxial anesthesia. The 4-month exam showed overall marked improvement; however, truncal blocks remained the most missed topic. Topics with 100% correct response rates in all examinations were local anesthetic pharmacology and systemic opioids. The results of this study indicate that a large portion of learning occurs during the first 4 months of the fellowship and slows thereafter. Using this simple form of fellowship evaluation, changes to an educational didactic curriculum can be implemented to reach medical knowledge goals more effectively and efficiently as required by the Accreditation Council for Graduate Medical Education.

Abstract No. : ABS0107 : Ultrasound guided lower thoracic erector spinae plane block for postoperative analgesia following gynaecologic oncology surgery - A randomised controlled trial

Background and Aims:Erector spinae plane (ESP) block is a relatively novel block which provides local and visceral analgesia for abdominal surgery. The present study is aimed to assess the efficacy of ESP block for postoperative analgesia following major open gynaecologic oncology surgery.Methods:Sixty female patients posted for elective open gynaecologic oncology surgeries were enroled in this prospective, double blind study and randomised to B and C group. Group B patients received general anaesthesia plus ultrasound guided bilateral ESP block at T9 level at the end of surgery while group C patients received general anaesthesia only. Primary outcome was postoperative visual analogue scale (VAS) scores. Secondary outcomes were time to first rescue analgesic, 24 hours tramadol consumption, and side effects. Chi square and student t tests were used and P < 0.05 was considered significant.Results:Postoperative pain scores were lower in B group compared to C group at rest and on movement . Time to first rescue analgesic was prolonged in B group (8.10 ± 1.48 hours) as compared to C group (0.7 ± 0.38 hours) [P < 0.0001]. Total 24 hours tramadol consumption was less in B group (68 ± 48.55 mg) than C group (210 ± 52.65 mg)(table 1) [P < 0.0001].Conclusion:Ultrasound guided ESP block with general anaesthesia provides superior postoperative analgesia compared to general anaesthesia alone following major gynaecologic oncology surgeries without any side effects. It can be used as an alternative to epidural analgesia.Table 1Comparison of variables in different routes of ketamine administrationVariableGroup intravenous-ketamineGroup nebulised-ketamine P Age mean (years)7.56±1.277.41±1.14>0.05Weight mean (kg)25.34±4.7125.09±2.97>0.05Parental Separation scores (median)11>0.05Sedation (median) 5-point sedation score22>0.05Verbal rating scale pain score (median) Immediate00>0.05 1 h- post-operatively210.04Time for 1st rescue analgesic (min)237.19±34.38 min300±26.396 minP<0.001

Observation and Analysis of the Postoperative Analgesic Effect of Subanaesthetic Dose of Ketamine in Kashin-Beck Disease Patients after Total Knee Arthroplasty.

With the transformation of modern medical models, the medical needs of patients have changed from treatment to safe, comfortable, and painless treatment. Therefore, it is clinically important to find an ideal analgesia model to reduce the pain after total knee arthroplasty and minimize the impact of surgical trauma on the body pressure. This article aims to study the effects of lower limb nerve block combined with local infiltration analgesia of the joint cavity on the hemodynamics and postoperative analgesia effects of knee joint replacement in elderly patients by comparing the effects of the subanaesthetic dose of ketamine on the hemodynamics and postoperative analgesia effect of knee joint replacement in elderly patients' intraoperative analgesia program. This article proposes that 90 patients requiring unilateral total knee replacement were randomly divided into 3 groups, with 30 patients in each group, age 65–85 years, average age 75 years, ASA I ∼ II grade, and body mass index 13.89 ∼ 37.26. Use a multifunctional monitor to monitor the patient's continuous blood pressure (SBP/DBP) and mean arterial pressure (MAP), heart rate (HR), electrocardiogram (ECG), intraoperative pulse oxygen saturation (SpO2), and end-tidal carbon dioxide (PETCO2). The following are monitored: record the heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure before induction of anesthesia (T0), before the upper tourniquet (T1), and after the upper tourniquet (T2), before tourniquet withdrawal (T3), and after tourniquet withdrawal (T4), mean arterial pressure (MAP). The three groups of patients had different degrees of itching, vomiting, nausea, and other adverse reactions. The experimental results in this article show that, in elderly patients with epidural anesthesia, the use of propofol and dexmedetomidine to maintain the patient's BIS value between 60 and 70 can meet the depth of sedation required for surgery without important surgical operation knowledge.

Long-Range Ordered Lamellar Formation with Lower Molecular Weight PS-PMMA Block Copolymers: Significant Effects of Discrete Oligopeptides at the Junction

Long-Range Ordered Lamellar Formation with Lower Molecular Weight PS-PMMA Block Copolymers: Significant Effects of Discrete Oligopeptides at the Junction

Influence of Block form on the Shear Behaviour of Soft Soil–Rock Mixtures by 3D Block Modelling Approaches

The influence of block forms on the shear behaviour of soil–rock mixtures with soft blocks (soft S–RMs) can be efficiently investigated by the discrete element method (DEM) on the basis of accurate 3D models accounting for the block breakage. This paper proposes a novel modelling approach, based on the spherical harmonics series, for the generation of 3D block geometries with different forms but same convexity and angularity. An already existing non-overlapping modelling approach was improved, characterized by a reduced computational cost, for the set-up of 3D block DEM models accounting for the block breakage. A number of soft S–RM DEM samples, subjected to numerical direct shear tests, were generated to analyze the influence of block forms and volumetric block proportion VBP on the mesoscopic and macroscopic behaviours. The results showed that the breakage degree is maximum for the spheroidal blocks, followed by the oblate, prolate and blade ones, due to the combined influence of the block frictional sliding and rotation. The shear strength of soft S–RMs is mainly controlled by the block interlocking and breakage, being maximum in the case of spheroidal block samples when the applied normal stress is low and in the case of prolate and blade ones for a high normal stress. It was found that a nonlinear Mohr–Coulomb criterion can provide a good description of the shear strength envelope of soft S–RMs. Soft S–RMs are characterized by a higher friction angle if composed by spheroidal and prolate blocks when the VBP is 40%, due to their elevated block interlocking, and in the case of prolate and blade blocks when the VBP is 60% at the higher normal stress, due to their lower block breakage degree.

Ultrasound-Guided Clavipectoral Fascial Plane Block With Intermediate Cervical Plexus Block for Midshaft Clavicular Surgery: A Prospective Randomized Controlled Trial.

Regional anesthesia such as interscalene brachial plexus block (ISBPB) with intermediate cervical plexus block (ICPB) is generally a preferred choice for clavicular surgery. However, various studies have shown that these blocks, especially ISBPB, could cause phrenic nerve paralysis and decrease diaphragmatic motion. The study aimed to evaluate the efficacy of clavipectoral fascial plane block (CPB), an alternative technique to ISBPB, with ICPB, in reducing hemidiaphragmatic paralysis during midshaft clavicular surgery. Forty patients scheduled for right midshaft clavicular surgery were randomized (1:1) into an ultrasound-guided ISBPB with ICPB (BC) group or ultrasound-guided CPB with ICPB (CC) group. Five milliliter of 0.375% ropivacaine was used for ICPB, another 20 mL for ISBPB or CPB, and no administration of additional sedative or general anesthetic was planned. Primary outcome was measured by the incidence of hemidiaphragmatic paralysis using M-mode ultrasonography, while secondary outcomes were measured by bedside pulmonary function test, the success rate of block, the time required for the block procedure and onset of block, and motor block score in right upper extremity. In comparison with BC group, the incidence of hemidiaphragmatic paralysis postblock was decreased in CC group (50% vs 0%; P < .001), and measurement of bedside pulmonary function was significantly improved. There was a 100% success rate for anesthetic block in both BC and CC groups, and CC group showed lower motor block score in upper extremity and less block procedure time than BC group (7.1 ± 1.2 vs 3.2 ± 0.6 minutes; P < .001). Moreover, no significant differences were found between time of onset of block and other anesthetic complications in the 2 groups. Ultrasound-guided CPB with ICPB could significantly reduce hemidiaphragmatic paralysis and provide an adequate surgical anesthesia with fewer complications such as motor block in upper extremity during right midshaft clavicular surgery.

Block Bregman Majorization Minimization with Extrapolation

In this paper, we consider a class of nonsmooth nonconvex optimization problems whose objective is the sum of a block relative smooth function and a proper and lower semicontinuous block separable function. Although the analysis of block proximal gradient (BPG) methods for the class of block $L$-smooth functions have been successfully extended to Bregman BPG methods that deal with the class of block relative smooth functions, accelerated Bregman BPG methods are scarce and challenging to design. Taking our inspiration from Nesterov-type acceleration and the majorization-minimization scheme, we propose a block alternating Bregman Majorization-Minimization framework with Extrapolation (BMME). We prove subsequential convergence of BMME to a first-order stationary point under mild assumptions, and study its global convergence under stronger conditions. We illustrate the effectiveness of BMME on the penalized orthogonal nonnegative matrix factorization problem.