Standardized Block Research Articles

Block Cipher Doubling for a Post-Quantum World

In order to maintain a similar security level in a post-quantum setting, many symmetric primitives should have to double their keys and increase their state sizes. So far, no generic way for doing this is known that would provide convincing quantum security guarantees. In this paper we propose a new generic construction, QuEME, that allows one to double the key and the state size of a block cipher in such a way that a decent level of quantum security is guaranteed. The QuEME design is inspired by the ECB-Mix-ECB (EME) construction, but is defined for a different choice of mixing function than what we have seen before, in order to withstand a new quantum superposition attack that we introduce as a side result: this quantum superposition attack exhibits a periodic property found in collisions and breaks EME and a large class of its variants. We prove that QuEME achieves n-bit security in the classical setting, where n is the block size of the underlying block cipher, and at least (n/6)-bit security in the quantum setting. We finally propose a concrete instantiation of this construction, called Double-AES, that is built with variants of the standardized AES-128 block cipher.

Outcomes in Patients With Vogt–Koyanagi–Harada Disease From the First-Line Antimetabolites for Steroid-Sparing Treatment Uveitis Trial

PurposeTo compare the effectiveness of methotrexate (MTX) and mycophenolate mofetil (MMF) in achieving corticosteroid-sparing control of uveitis in patients with Vogt-Koyanagi-Harada (VKH) disease. MethodsA subanalysis of patients with VKH from the First-line Antimetabolites as Steroid-sparing Treatment (FAST) Uveitis Trial, a randomized, observer-masked, comparative effectiveness trial, with comparisons by treatment (MTX versus MMF) and disease stage (acute versus chronic). Individuals with noninfectious uveitis were placed on a standardized corticosteroid taper and block randomized 1:1 to either 25mg weekly oral MTX or 1.5g twice daily oral MMF. The primary outcome was treatment success defined by corticosteroid-sparing control of uveitis at 6 months. Additional outcomes included change in best spectacle-corrected visual acuity (BSCVA), retinal central subfield thickness (CST), and resolution of serous retinal detachment (SRD). ResultsNinety-three out of 216 enrolled patients had VKH; 49 patients were randomized to MTX and 44 to MMF, of which 85 patients (46 on MTX, 39 on MMF) contributed to the primary outcome. There was no significant difference in treatment success by antimetabolite (80.4% for MTX compared to 64.1% for MMF; P=.12) or in BSCVA improvement (P=.78). Methotrexate was superior to MMF in reducing CST (P=.003) and resolving SRD (P=.02). There was no significant difference in treatment success by disease stage (P=.25), but patients with acute VKH had greater improvement in BSCVA (P<.001) and reduction of CST (P=.02) than chronic VKH patients. ConclusionsMTX and MMF have comparable outcomes as corticosteroid-sparing immunosuppressive therapies for VKH. Visual acuity improvement was greater in acute vs chronic VKH. Trial RegistrationClinicalTrials.gov Identifier: NCT 0182929

Battle of the Blocks: Which Pain Management Technique Triumphs in Gender-Affirming Bilateral Mastectomies?

Gender-affirming mastectomy, performed on transgender men and non-binary individuals, frequently leads to considerable postoperative pain. This pain can significantly affect both patient satisfaction and the overall recovery process. The study examines the efficacy of four analgesic techniques pectoral nerve (PECS) 2 block, erector spinae plane (ESP) block, thoracic wall local anesthesia infiltration (TWI), and systemic multimodal analgesia (SMA) in managing perioperative pain, with special consideration for the effects of chronic testosterone therapy on pain thresholds. A retrospective analysis was conducted on patients aged 18 - 45 who underwent gender-affirming bilateral mastectomies at a New York City community hospital. The study compared intraoperative and post-anesthesia care unit (PACU) opioid consumption, postoperative pain scores, the interval to first rescue analgesia, and total PACU duration among the four analgesic techniques. The study found significant differences in intraoperative and PACU opioid consumption across the groups, with the PECS 2 block group showing the least opioid requirement. The PACU morphine milligram equivalent (MME) consumption was highest in the SMA group. Postoperative pain scores were significantly lower in the PECS and ESP groups at earlier time points post-surgery. However, by postoperative day 2, pain scores did not significantly differ among the groups. Chronic testosterone therapy did not significantly impact intraoperative opioid requirements. The PECS 2 block is superior in reducing overall opioid consumption and providing effective postoperative pain control in gender-affirming mastectomies. The study underscores the importance of tailoring pain management strategies to the unique physiological responses of the transgender and non-binary community. Future research should focus on prospective designs, standardized block techniques, and the complex relationship between hormonal therapy and pain perception.

Analgesia efficacy of lidocaine transfused by a novel disposable injectable cervical dilator during intrauterine device removal procedure: A randomized clinical trial

ObjectiveThe majority of intrauterine devices (IUDs) inserted in China are tailless, requiring intrauterine manipulations for removal and causing pain. This study aimed to investigate the analgesic efficacy of lidocaine injection into a novel disposable injectable cervical dilator for IUD removal procedures. Study designA double-blinded, placebo-controlled, randomized clinical trial was conducted with women aged 18–65 years old requesting outpatient IUD removal. The study randomly assigned participants to either lidocaine (injecting 5 ml of 2% lidocaine into the injectable cervical dilator) or placebo (injecting 5 ml of normal saline into the device) group. All participants received a standardized paracervical block. The primary outcome was pain reported during IUD removal on a 100 mm Visual Analog Scale (VAS). Intention-to-treat were conducted to evaluate the analgesic effectiveness of injecting lidocaine into the injectable cervical dilators. ResultsWe enrolled seventy-four eligible participants (37 in lidocaine group and 37 in placebo group). The results showed that the median intraoperative VAS score in the lidocaine group was lower than the placebo group (30.0 mm [IQR 20.0–46.0, n = 37] vs 46.0 mm [IQR 30.0–55.0, n = 37], p = 0.01. In subgroup analyses, among participants with IUD removal and without uterine manipulation and additional procedures, there was no statistically significant disparity observed in intraoperative VAS scores between the lidocaine and placebo group (15.0 mm [IQR 10.0–27.5, n = 8] vs 20.0 mm [IQR 20.0–40.0, n = 6]), p = 0.28). Among participants with an IUD removal necessitating intrauterine manipulations and without additional procedures, showing lower intraoperative VAS scores in lidocaine group (25.0 mm [IQR 15.0–40.5, n = 17]) compared to placebo group (46.0 mm [IQR 38.5–50.0, n = 23]), p < 0.01. Among participants with additional procedures in addition to IUD removal, there was no statistically significant disparity observed in intraoperative VAS scores between the lidocaine and placebo group (41.0 mm [IQR 32.5–57.5, n = 12] vs 45.0 mm [IQR 22.5–69.0, n = 8]), p = 0.97). ConclusionsInjecting lidocaine into the novel disposable injectable cervical dilator for cervix dilation can significantly reduce pain during an IUD removal, particularly in patients necessitating intrauterine manipulations during IUD removal. ImplicationsWhen we have to perform intrauterine manipulations to remove an IUD, surgical pain and narrow cervical canal undoubtedly affect the implementation of the procedure. Injecting lidocaine into the injectable cervical dilator can achieve local anesthesia while dilating the cervix, and might reduce the choice of general anesthesia for IUD removal.

Study of the effect of bio-inspired surface texture on the shear strength of bonded 3D-printed materials: Comparison between stainless steel and polycarbonate joints

Additive Manufacturing (AM) is one of the important technological pillars of Industry 4.0. Thanks to its tool-free manufacturing and extreme flexibility, AM has the potential to respond to individual customer preferences with a customized final product. Nevertheless, the size of 3D printed products is limited by the size of the build chamber of commercially available printers. In addition, deformations, stability, tolerances, and especially cost are highly dependent on the maximum size of the parts. Therefore, a larger final product can only be realized as an assembly group. Therefore, adhesive bonding appears to be an attractive solution for assembling parts made by AM. In this paper, a comparison of the influence of surface texture on the shear strength of 3D-printed metallic and polymeric adhesive joints was performed. A fish scale (FS) bio-inspired surface texture was chosen to examine how surface patterning influences the strength of joints. Fused deposition modeling (FDM) and selective laser melting (SLM) techniques were used to produce polycarbonate (PC) and stainless steel (17-4 PH) specimens, respectively. The effect of bio-surface and material type on the shear strength of adhesive joints was assessed using the ASTM D4501 standardized block shear testing method. The morphological analysis revealed that FDM exhibits reduced resolution and accuracy, making it less suitable for the additive manufacturing of complex surface features in 3D-printed parts when compared to SLM technology. In addition, bio-surface texturing significantly improved the wettability of stainless steel, requiring the synergy of higher surface free energy and increased surface roughness (FS bio-surface) for super-hydrophilicity, while a combination with lower surface free energy (PC material) and the same surface roughness resulted in hydrophobic behavior. On the other hand, the bio-surface texture greatly enhanced the shear strength (+31%) of stainless steel specimens, compared to PC specimens, due to the increase of physical adsorption forces and the enhancement of the mechanical interlocking effect. The analysis of variance (ANOVA) results highlight the predominant influence of material type on surface wettability (84%), while surface texture has a more pronounced impact on the shear strength of bonded joints (71%).

Insights into the daily life of ventricular assist device coordinators-Outcome of an international questionnaire.

As the incidence of heart failure in developed countries is on the rise, mechanical circulatory support (MCS) often remains the only treatment option for patients with end-stage heart failure and is well established worldwide. Even though VAD coordinators play a key role in VAD programs, their responsibilities and daily duties are not clearly defined and characterized. Recently published data from the first 5-year multicenter clinical trial assessing experience with the HeartMate 3 left ventricular system (Abbott, Abbott Park, IL) show an overall survival of 61% at 5 years. When it comes to possible improvements to these systems, it is necessary for developers not only to know the status quo but also to determine and consider the visions and wishes of those individuals who take care of patients, provide education and deal with possible complications. This would be helpful a meaningful effort towards implementing a standard of care. To fill this knowledge gap, we conducted an online survey using the SurveyMonkey tool, addressing representatives of programs implanting VADs worldwide. Representatives answered a standardized block of 14 questions and were asked to provide responses within 3 months. A total of 91 VAD coordinators from centers of various regions of the world completed the survey. The majority came from European countries. The numbers of patients followed up by the centers ranged from <20 to 390 patients. The majority of VAD coordinators had a nursing background (68%). Seventy-seven percent of the centers operate a 24-h hotline and 3-monthly visits to the outpatient department are most common. Fifty-nine percent of the centers do not use an infection scoring system for driveline wound care. The majority of the centers indicated that an optimized follow-up concept including wound care, medication, and social care is crucial and the key issue for an improved outcome. Smaller components and intensified psychosocial support ranked highest in questions about how to improve quality of life. Surprisingly, the future prospects of telemetric monitoring were not rated high in significance. There is a wide variability in the composition and tasks of VAD programs worldwide. Implementing a standard of care and improving psychosocial care as well as equipment is regardedmost important to improve outcomes and quality of life. From the point of view of those responsible, the significance of telemetric monitoring seemed overrated.

Microgrid Building Blocks: Concept and Feasibility

For power grids with high penetration of distributed energy resources (DERs), microgrids can provide operation and control capabilities for clusters of DERs and load. Furthermore, microgrids enhance resilience of the hosting bulk power grid if they are enabled to serve critical load beyond the jurisdiction of the microgrids. For widespread deployment of microgrids, a modular and standardized Microgrid Building Block (MBB) is essential to help reduce the cost and increase reliability. This paper proposes the conceptual design of an MBB with integrated features of power conversion, control, and communications, resulting in a systemwide controller for the entire microgrid. The results of a feasibility study indicate that, in a utility-connected mode, MBB-based microgrids can exchange power with the hosting power grid while serving regulation and optimal dispatch functions. In a resiliency (islanded) mode when the microgrid is disconnected from the utility system, the MBB control system acts to stabilize the system frequency and voltage under small or large disturbances. The microgrid controller is supported by a communication system that meets the latency requirements imposed by the microgrid dynamics as well as data acquisition time. The extended IEEE 13-node system is used as a microgrid model to validate the proposed MBB design and functionality.

Investigating the magnetic resonance imaging cross-section area that best correlates with intraoperative hamstring autograft size.

This study aimed to find out the level of the gracilis and semitendinosus tendons that would provide the closest information about the size of the quadruple-stranded hamstring autograft using magnetic resonance images before anterior cruciate ligament reconstruction. Ninety-six patients (44 males, 52 females) who underwent anterior cruciate ligament reconstruction with quadruple hamstring tendon autografts between January 2015 and March 2020 were retrospectively analyzed. The cross-sectional areas of the gracilis and the semitendinosus tendons at 6 different levels (pes anserinus insertion site, tibial tuberosity, fibular head, tibial plateau, and the proximal insertion sites of the anterior cruciate ligament and the medial collateral ligament were measured on the magnetic resonance images. In addition, the harvested hamstring tendons were measured together (quadrupled) using a standardized graft-sizing block. There was no significant difference between genders in terms of the tendon sizes measured in all levels using magnetic resonance images. There was a strong correlation between the graft size and the measurements made at the tibial plateau level (P < .0001, r=0.590). Intraoperative quadruple hamstring tendon sizes were most correlated with the magnetic resonance image measurements at the tibial plateau level. To use a hamstring autograft with a diameter of at least 8 mm for anterior cruciate ligament reconstruction, the total area of the 2 tendons should be at least 18.11 mm2 in the magnetic resonance image measurements made at the tibial plateau level. Level IV, Diagnostic Study.

P20. Evaluation of interbody design parameters on graft subsidence in the 3D-printed era: separating fact from fiction

<h3>BACKGROUND CONTEXT</h3> Cage subsidence is a known complication of spinal interbody fusion and is associated with poor clinical outcomes. Three-dimensional-printed titanium interbodies are becoming increasingly popular and their unique manufacturing allows for alteration of several features including stiffness and porosity. Though there are many claims made regarding the influence of these features on interbody subsidence, there is a lack of rigorous scientific evaluation. <h3>PURPOSE</h3> The purpose of this study is to determine how changes in implant parameters biomechanically affect subsidence using an in-vitro sawbone model. <h3>STUDY DESIGN/SETTING</h3> In vtiro biomechanical saw bone model. <h3>OUTCOME MEASURES</h3> Subsidence measured as relative displacement of the interbody and foam block using digital imaging correlation. Stiffness measured using thethe linear portion of the load displacement curve. <h3>METHODS</h3> Eight groups were tested (n = 8/group) including seven 3D-printed titanium (Seaspine, Inc.) varying in surface area (aperture: standard, small and none), porosity (high vs low) and surface topography (nonporous vs porous) as well as one standard PEEK and one solid titanium. Subsidence testing was performed in a standardized foam block model compressed to 150 N, cycled between 50-250N for 5000 cycles at a rate of 1 Hz. Digital imaging correlation was used to determine relative displacement of the interbody and foam block. Stiffness testing was performed by compressing implants between parallel steel blocks by 500 N at a rate of 50N/sec for three cycles and measuring the linear portion of the load displacement curve. <h3>RESULTS</h3> Subsidence was decreased as the surface area of contact with the sawbone was increased (all p 0.353) or based on material property (all p>.192). Apparent stiffness of the implant was affected by porosity (p 0.146). The PEEK cage had similar stiffness to porous Ti (p= 0.959). A nonporous surface led to greater stiffness compared to the standard porous interbody (p= 0.010). Surface area was negatively correlated with subsidence (r= -0.808, p=0.0284), but was not correlated with stiffness (r= 0.568, p=0.183). <h3>CONCLUSIONS</h3> Implant surface area and surface topography have the greatest influence on interbody subsidence. Apparent stiffness, implant porosity, as well as material property do not affect subsidence in an in vitro model. Biologic response in the in vivo setting likely also influences clinical subsidence, which is a topic of future study. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Efficient Implementation of AES-CTR and AES-ECB on GPUs With Applications for High-Speed FrodoKEM and Exhaustive Key Search

The Advanced Encryption Standard (AES) is a standardized block cipher widely used to protect data confidentiality. Besides that, it can be used to generate pseudo-random numbers, which has many important applications. Recently, several works demonstrated the efficient implementations of AES electronics code book (ECB) and counter (CTR) mode on GPU platforms, achieving high throughput. In this brief, we set a speed record of AES implementation, which outperformed previous implementations. In particular, the proposed AES implementation achieved throughput 9&#x0025; (CTR) and 7&#x0025; (ECB) higher than the state-of-the-art, bit-sliced implementation. Moreover, the proposed technique does not require round keys to be embedded into the code during compilation, which is a serious limitation found in earlier work. The proposed technique also achieved up to 63&#x0025; higher throughput compared to another technique presented recently. Two use cases are presented here to verify the efficiency of the proposed AES implementation. Firstly, AES is used to generate random samples in a NIST post-quantum key encapsulation mechanism (KEM), achieving 3,350, 1,503 and 7,716 key exchanges per second on V100, T4, and RTX3080 GPUs respectively. This allows the proposed FrodoKEM implementation to be <inline-formula> <tex-math notation="LaTeX">$2.99\times $ </tex-math></inline-formula> faster than the state-of-the-art performance. The proposed AES implementation was also used in an exhaustive key search application, achieving 11,428, 3,969, and 9,998 <inline-formula> <tex-math notation="LaTeX">$\times 10^{6}$ </tex-math></inline-formula> encryptions per second on V100, T4, and RTX3080 GPUs, respectively.

Intranasal fentanyl for first-trimester uterine aspiration pain: A randomized controlled trial

ObjectiveTo evaluate whether administration of intranasal fentanyl reduces reported pain during first-trimester uterine aspiration. Study DesignWe conducted a multicenter, randomized, double-blind, placebo-controlled trial of patients with pregnancies less than or equal to 14 weeks gestation seeking uterine aspiration for induced abortion, early pregnancy loss, or failed medication abortion. We randomized participants 1:1 to either intranasal fentanyl 100 mcg or intranasal placebo. All participants received ibuprofen and a standardized paracervical block. The primary outcome was pain indicated at the time of uterine aspiration on a 100 mm visual analog scale (VAS). We designed the study to detect a 15 mm difference in mean pain scores, which required 53 people in each arm for a total of 106 participants. Secondary outcomes included postprocedure pain and patient satisfaction with pain control. ResultsFrom March 2017 through June 2018, we screened 355 people for eligibility and enrolled 107 participants. Those who received intranasal fentanyl reported similar uterine aspiration pain to participants who received placebo (58.4 ± 28.0 fentanyl vs 58.6 ± 24.5 placebo, p = 0.97). Participants who received intranasal fentanyl also reported similar postprocedure pain scores compared to participants who received placebo (19.1 ± 19.4 fentanyl vs 17.2 ± 19 placebo, p = 0.63), and were equally satisfied with procedure pain control (66.8 ± 31.2 fentanyl vs 63.3 ± 29.2 placebo, p = 0.57). ConclusionIntranasal fentanyl did not decrease reported pain with first-trimester uterine aspiration, nor did it decrease postprocedure pain compared to placebo. As an adjunct to ibuprofen and paracervical block, intranasal fentanyl did not improve patient satisfaction with pain control. ImplicationsIntranasal fentanyl does not reduce reported pain with first-trimester uterine aspiration, however abortion-seeking patients are amenable to receiving intranasal medications for pain management.

METHODS OF EDUCATIONAL FACILITY DESIGN USING UNIFIED BLOCK UNITS

The article covers the effective methods of a timesaving public facility design and construction and specifies the method of the kindergarten and primary school design using unified block units. The war started by the hostile country against Ukraine has completely changed our lives. Demolished houses and public buildings, industrial facilities, the infrastructure, whole villages and cities became striking realities that challenged the architects and urban designers to solve the issue of prompt and complex reconstruction in the cities. Because of the war, Ukraine will soon face the demand for fast residential area development and complex construction of facilities, such as kindergartens and secondary schools, raising concerns on the effective methods of timesaving public facility design and construction. At the end of the twentieth century, an expert team at the Kiev National University of Construction and Architecture developed a standardized unit block system for housing and public areas prompting the unified block unit residential building and public area construction.&#x0D; The block-modular method can be used in present environment for educational facility construction, considering the architectural and construction trends. To outline the practices and structure the typical evaluation at educational facility design, the following diverse unified functional elements were introduced: a single and a double block of cells for a kindergarten; one, two and three-unit assembly standardized functional block for a primary school educational area; a standardized functional block of common use sharing kindergarten premises and primary school.

Torque acting on biodegradable magnesium screws during intramedullary insertion into a metacarpal bone – a biomechanical study

Recently, biodegradable implants made from magnesium (Mg) alloys have been developed to obviate the need for later implant removal. Mg-based cannulated compression screws (CCS) are ideal for intramedullary screw (IMS) fixation of metacarpal fractures. The present study aimed at investigating the torque acting on Mg-based CCS at failure and at intramedullary metacarpal insertion. The devices were CE certified Magnezix 2.7 and 3.2 mm CCSs (Syntellix®, Hannover, Germany). Torque at failure was measured in a synthetic bone model using a standardized polyurethane foam block. In a second assessment, insertional torque was measured in ten cadaveric metacarpal bones. Mean torque at failure for the 2.7 mm and 3.2 mm CCSs was 42.8 Ncm (±1.9 Ncm) and 63.0 Ncm (±2.2 Ncm), respectively. In the human cadaver model, the torque distribution curve at metacarpal insertion showed three peaks. The highest reached 53.6% of the lowest torque at failure measured in the synthetic bone model for the 3.2 CCS (31.4 vs. 58.6 Ncm). The mean difference between peak torque at metacarpal insertion and torque at failure was 38.3 Ncm (99% CI [33.6, 43.0 Ncm], p < 0.0001). In terms of torque load, Mg-based CCSs are suitable for IMS fixation of metacarpal fractures. Biodegradable implants may represent an important improvement of this treatment method; confirmation by in-vivo studies is needed.

Will the Use of Intraoperative Liposomal Bupivacaine During Thumb Carpometacarpal Arthroplasty Decrease Postoperative Use of Opioids? A Prospective Randomized Study

This study evaluated the use of intraoperative local injection of liposomal bupivacaine to decrease opioid use in the early postoperative period for patients undergoing outpatient thumb carpometacarpal joint arthroplasty. A prospective, randomized, controlled, single-blinded study was designed to compare 2 groups of patients for opioid use, pain scores, and nonopioid pill consumption within 5 days after surgery. The investigational group received an intraoperative injection of 10 ml (133 mg) liposomal bupivacaine. The control group received no local anesthetic. All patients were anesthetized with a standardized supraclavicular nerve block and were prescribed equal amounts of oral narcotic analgesic. Outcomes were assessed by collecting the data from postoperative patient-reported diaries. The experimental group reported a significantly lower total opioid consumption for the 5 days after surgery. Daily opioid use, as measured by both opioid pill equivalent count and morphine milligram equivalent in addition to postoperative pain scores and nonopioid pill consumption, was not different between groups. Intraoperative injection of liposomal bupivacaine was shown to decrease total opioid intake during the 5 days after thumb carpometacarpal arthroplasty. Therapeutic II.

Comparative evaluation of cyclic fatigue resistance of file systems based on different manufacturing technologies after exposure to NaOCl and multiple sterilization cycles

Aim: To comparatively evaluate in vitro the cyclic fatigue resistance of different file systems based on different manufacturing technologies after exposure to NaOCl and multiple sterilization cycles.Materials and Methods: Sixty new Nickel − Titanium (NiTi) rotary files were selected and divided into five groups (n = 12) based on different manufacturing technology. These groups were: Protaper Universal (GPT) (DentsplyMaillefer, Ballaigues, Switzerland) Protaper Next (GPTN) (Dentsply, Tulsa, OK, USA), Twisted files (GTF) (Sybron Endo, Orange, CA, USA), Neoniti (GNL) (Neolix, France), and Hyflex CM (GHCM) (Coltene/whaledent inc., 235 Ascort Parkway, Cuyahoga falls, OH, USA). Files were sterilized in an autoclave at 121°C at 15 psi for 15 min and exposed to 5.0% NaOCl solution for 30 s before cyclic fatigue testing till instrument fracture using a standardized grooved block assembly with the artificial canal at 90° angle of curvature using a 16:1 reduction hand-piece powered by a torque-controlled motor. This whole procedure of autoclaving, immersion in sodium hypochlorite solution and rotating in a stainless steel assembly was repeated again and again until the file fractured.Results: The highest mean for the number of cycles before fracture was observed with Neoniti (GNL) and lowest for Hyflex CM (GHCM). The difference between GPT vs GTF, GPTvs GNL, GNLvs GHCM; GPTNvs GTF, GPTNvs GNL, GPTNvs GHCM; GTFvs GNL, GTFvs GHCM and GNL VS GHCM was statistically significant, whereas the difference between GPTvs GPTN was statistically nonsignificant.Conclusion: Neoniti and twisted file systems resisted the maximum number of cycles to fracture at 90° angle of curvature after exposure to 5% sodium hypochlorite solution and multiple autoclaving cycles. Hyflex CM showed the least resistance in the similar conditions.

On the impossibility of an invariant attack on Kuznyechik

Currently numerous cryptographic systems are based on SP-networks. These primitives are supposed to be secure but recent investigations show that some attacks are possible. The aim of this work is to study how secure the Russian standardized block cipher Kuznyechik over invariant attacks. We study the already known decompositions of its permutation and show the ways of constructing invariant subsets. A new approach to invariant attacks is presented and it proves that there are no subsets based on S-Box properties that are invariant under round functions of Kuznyechik.

Postanesthetic Cold Sensibility Test as an Indicator for the Efficacy of Inferior Alveolar Nerve Block in Patients with Symptomatic Irreversible Pulpitis of Mandibular Molars.

Materials and Methods This study was conducted on the mandibular first molars of 54 patients (35 males and 19 females) with signs and symptoms of SIP. To anesthetize the affected molars, all patients received a single carpule of 2% lidocaine with 1 : 100000 epinephrine using a standardized inferior alveolar nerve block (IANB) technique. The cold test was conducted before beginning the endodontic procedures and after gaining lip numbness, and the results were reported as either positive or negative response. The root canal preparation (RCP) was then initiated and the patients' responses were documented (Gold standard test). True pulpal anesthetic failure was described as a pain perception during the access cavity and pulp tissue removal. True pulpal anesthesia was defined as no pain or discomfort during the access cavity and pulp extirpation. The qualitative variables frequencies and percentages of patients with true/false positive and negative responses were determined and then compared using the Chi-square test. The pain perception of male and female patients during the cold test and gold standard was compared using the Fisher exact test. The following diagnostic parameters were calculated using an online statistical calculator: sensitivity, specificity, predictive values, accuracy, and Youden index. In addition, a receiver operating characteristic curve (ROC) was constructed and the area under the curve (AUC) was calculated. Results The overall percentage of actual failure of pupal anesthesia was 57%. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and Youden index for the cold test were 0.87, 0.91, 0.93, 0.84, 0.89, and 0.78, respectively. There was no statistically significant difference between male and female patients regarding their responses to cold testing and the gold standard test (P > 0.05). Besides, the patients' reactions to the cold test were significantly matched with their reactions to the gold standard test (P < 0.05). The area under the ROC was mostly 0.9. Conclusion The cold test could be a valuable and accurate method for predicting the potential pupal anesthesia before beginning the endodontic treatment of mandibular molars with symptomatic irreversible pulpitis, particularly after obtaining postanesthetic soft tissue numbness.

Suspension button constructs restore posterior knee laxity in solid tibial avulsion of the posterior cruciate ligament

PurposeDislocated tibial avulsions of the posterior cruciate ligament (PCL) require surgical intervention. Several arthroscopic strategies are options to fix the fragment and restore posterior laxity, including two types of suspension button devices: adjustable (self-locking) and rigid knotted systems. Our hypothesis was that a rigid knotted button construct has superior biomechanical properties regarding laxity restoration compared with an adjustable system. Both techniques were compared with standard screw fixation and the native PCL.MethodsSixty porcine knees were dissected. The constructs were tested for elongation, stiffness, yield force, load to failure force, and failure mode in a material testing machine. Group N (native, intact PCL) was used as a control group. In group DB (Dogbone™), TR (Tightrope™), and S (screw), a standardized block osteotomy with the osteotomized fragment attached to the PCL was set. The DB and TR groups simulated using a suspension button system with either a rigid knotted (DB) or adjustable system (TR). These groups were compared to a screw technique (S) simulating antegrade screw fixation from posterior.ResultsComparing the different techniques (DB, TR, S), no significant elongation was detected; all techniques achieved a sufficient posterior laxity restoration. Significant elongation in the DB and TR group was detected compared with the native PCL (N). In contrast, screw fixation did not lead to significant elongation. The stiffness, yield load, and load to failure force did not differ significantly between the techniques. None of the techniques reached the same level of yield load and load to failure force as the intact state.ConclusionArthroscopic suspension button techniques sufficiently restore the posterior laxity and gain a comparable construct strength as an open antegrade screw fixation.

Comparison of 0.125% and 0.2% ropivacaine in continuous lumbar plexus block for postoperative analgesia after total hip arthroplasty

Background: Lower concentrations of ropivacaine in continuous lumbar plexus block (LPB) have not been studied adequately. Thus, we designed this prospective, randomized, comparative study to evaluate the two different concentrations of ropivacaine (0.125% and 0.2%) in continuous LPB for postoperative pain relief following total hip arthroplasty (THA). Materials and Methods: Fifty patients undergoing THA under standardized subarachnoid block have been randomly allocated to receive a continuous infusion of either 0.125% (Group 1) or 0.2% (Group 2) of ropivacaine in LPB done under the guidance of peripheral nerve stimulator. The primary outcome was consumption of tramadol during the first 24 h and the secondary outcomes were quality of sensory and motor blockade and consumption of ropivacaine. Results: The total amount of tramadol did not differ significantly (P = 0.442) between the two groups. Furthermore, the duration of sensory and motor blockade did not differ significantly between the two groups. However, the average consumption of ropivacaine was significantly lower in Group 1 when compared to Group 2 (238.80 mg vs. 380.64 mg, P = 0.0001). Conclusion: Administration of 0.125% of ropivacaine can be a better alternative as it would decrease the total amount of the local anesthetic in continuous LPB.

Fascial Plane Blocks: More Questions Than Answers?

Fascial Plane Blocks: More Questions Than Answers?