Three-dimensional reduction method with a modified C2 isthmus screw in irreducible atlantoaxial dislocation: a technical note

Background Three-dimensional reduction plays a vital role in surgical reduction of irreversible atlantoaxial dislocation (IAAD). However, the most commonly used combination of C1 pedicle screw (PS) or lateral mass screw (LMS) and C2 PS or isthmus screw often fails to achieve satisfactory reduction at one time. The difficulty is usually caused by short anteroposterior and vertical distance between heads of C1 and C2 screws, which lack enough space for reduction operation. The objective of this study is to describe a three-dimensional reduction method with a modified C2 isthmus screw and to illustrate its advantage and effectiveness for IAAD. Methods Twelve patients with IAAD underwent reduction and fixation with modified C2 isthmus screw combined with C1 PS or LMS, fusion with autologous bone graft. The insertion point was lateral to the intersection of caudal edge of C2 lamina and lateral mass, with a trajectory towards C2 isthmus, via lateral mass. The three-dimensional reduction was achieved through pulling and distracting. Radiographic evaluation included anteroposterior and direct distance between different insertion points, the occipitoaxial angle (O-C2A), clivus-canal angle (CCA) and cervicomedullary angle (CMA). Clinical outcomes evaluation included the Japanese Orthopaedic Association (JOA) score, Visual analog scale (VAS) and Neck Disability Index (NDI). Results All the patients maintained effective reduction during the follow-up. The anteroposterior and direct distance was significantly higher in modified C2 isthmus screw than C2 PS whether combined with C1 PS or LMS (P < 0.05). The degree of O-C2A, CCA and CMA, JOA score, NDI, and VAS were significantly improved after the surgery (P < 0.05). Conclusions Three-dimensional reduction method with a modified C2 isthmus screw is effective and safe in managing IAAD. It can increase the anteroposterior and vertical distance between the heads of C1 and C2 screws, which is benefit for the three-dimensional reduction operation of IAAD.

Fractal mathematical over extended finite fields Fp[x]/(f(x))

In this paper, we have defined an algorithm for the construction of iterative operations, based on dimensional projections and correspondence between the properties of extended fields, with respect to modular reduction. For a field with product operations R(x) ⊗ D(x), over finite fields, GF[(pm)n−k]. With Gp[x]/(g(f(x)), whence the coefficient of the g(x) is replaced after a modular reduction operation, with characteristic p. Thus, the reduced coefficients of the generating polynomial of G contain embedded the modular reduction and thus simplify operations that contain basic finite fields. The algorithm describes the process of construction of the GF multiplier, it can start at any stage of LFSR; it is shift the sequence of operation, from this point on, thanks to the concurrent adaptation, to optimize the energy consumption of the GF iterative multiplier circuit, we can claim that this method is more efficient. From this, it was realized the mathematical formalization of the characteristics of the iterative operations on the extended finite fields has been developed, we are applying a algorithm several times over the coefficients in the smaller field and then in the extended field, concurrent form.

Pengembangan Media Pembelajaran Permainan Ludo Pada Materi Operasi Pengurangan Kelas 3 MIS Sindangraja

This research and development is motivated by the existence of potentials and problems, the potential in this study regarding several learning media that can stimulate or facilitate the learning process. Whereas the problem is that students do not understand the subtraction operation so they have to explain the material repeatedly, this is because there is no stimulus to support the learning process. This can be proven by the average value of 70, and the KKM score in these subjects 75. So it can be concluded that the average score is less than the KKM value. Therefore, a learning media is needed based on these potentials and problems. So that ludo game learning media was created in the MIS Sindangraja class 3 reduction operation. This research is included in the type and design of research development or R&D (Research and Development) of the Borg and Gall type which was carried out at the Sindangraja MIS School with a total of 16 students. The data collection technique was done by using prestest and postest tests. Data were analyzed by SPSS.

Study of tube billet reduction to obtain constant wall thickness

Analysis of material thickening process during reduction operation is presented. In order to obtain constant thickness after reduction by conical die thickness distribution of the workpiece is proposed. Workpiece with required thickness distribution is manufactured by thinning drawing. Experimental verification of proposed thickness distribution in order to obtain constant thickness after reduction operation is carried out.

Efficient implementation of modular multiplication over 192-bit NIST prime for 8-bit AVR-based sensor node

Modular multiplication is one of the most time-consuming operations that account for almost 80% of computational overhead in a scalar multiplication in elliptic curve cryptography. In this paper, we present a new speed record for modular multiplication over 192-bit NIST prime P-192 on 8-bit AVR ATmega microcontrollers. We propose a new integer representation named Range Shifted Representation (RSR) which enables an efficient merging of the reduction operation into the subtractive Karatsuba multiplication. This merging results in a dramatic optimization in the intermediate accumulation of modular multiplication by reducing a significant amount of unnecessary memory access as well as the number of addition operations. Our merged modular multiplication on RSR is designed to have two duplicated groups of 96-bit intermediate values during accumulation. Hence, only one accumulation of the group is required and the result can be used twice. Consequently, we significantly reduce the number of load/store instructions which are known to be one of the most time-consuming operations for modular multiplication on constrained devices. Our implementation requires only 2888 cycles for the modular multiplication of 192-bit integers and outperforms the previous best result for modular multiplication over P-192 by a factor of 17%. In addition, our modular multiplication is even faster than the Karatsuba multiplication (without reduction) which achieved a speed record for multiplication on AVR processor.

Application of Wire-Assisted Reduction Guided by Minimally Invasive Wire Introducer in the Treatment of Irreducible Femoral Intertrochanteric Fractures

Background: Open reduction was often required in the treatment of irreducible femoral intertrochanteric fractures. A minimally invasive wire introducer was designed to assist the reduction of such fractures. The aim of our study was to investigate the clinical outcomes of this technique.Methods: Between 2013 and 2018, 92 femoral intertrochanteric fracture patients who were treated with intramedullary nail fixation and difficult reduction using the traction beds were retrospectively reviewed. Decision for surgery was based on the displacement of the fracture. The patients was divided into two groups, 31 in the control group and 61 in the observation group. The control group were received open reduction operation. And the observation group still received the closed reduction operation, using minimally invasive wire introducer to guide the wire and assist the fracture reduction. The operation time, blood loss, VAS scores, angulation, reduction, neck-shaft angle, redisplacement, limb length discrepancy, and union time were recorded.Results: All patients of two groups were successfully operated and were followed up for an average of 23.8 months. There was no statistical difference in baseline data between the two groups. The observation group had shorter operation time, lower VAS score and less intraoperative bleeding. And the datas are statistically different.Conclusion: Minimally invasive wire introducer is a good technology to guide the wire for irreduciblr femoral intertrochanteric fracture reduction. Using this technique, irreduciblr femoral intertrochanteric fractures could be restored and good clinical outcome was achieved.Level of evidence: Level IV; Case Series; Treatment Study

Turbinate Submucosal Reduction Operation Reduced Migraine Admission among Patients with Chronic Hypertrophic Rhinitis

Rhinitis increases migraine risk. Chronic hypertrophic rhinitis can be treated with turbinate submucosal reduction operation. The relationship between migraine and chronic hypertrophic rhinitis after turbinate submucosal reduction operation is still unclear. The goal of this study was to evaluate the correlation between turbinate submucosal reduction operation and subsequent migraine admission in Asian chronic hypertrophic rhinitis patients. We identified patients suffering from chronic hypertrophic rhinitis and receiving turbinate submucosal reduction operation. The control group was selected from patients with chronic hypertrophic rhinitis without operation. The event was migraine admission. The risk factors of migraine admission were established using multivariate Cox proportional hazard regression. The risk of migraine admission after turbinate submucosal reduction operation is represented by a hazard ratio (HR) of 0.858 (95% confidence interval (CI): 0.633–0.962). The higher risk of migraine included depression with HR 4.348 (95% CI: 2.826–6.69), anxiety with HR 3.75 (95% CI: 2.267–6.203), fibromyalgia with HR of 7.326 (95% CI: 3.427–15.661), and asthma with HR 1.969 (95% CI: 1.11–3.491). Our study revealed that turbinate submucosal reduction operation led to a 14.2% reduction in migraine admission. Clinicians should understand the benefit of turbinate submucosal reduction operation and provide suitable treatments for comorbid conditions. Further prospective studies are required to confirm our findings.