342 research outputs found
HOMOGENIZATION OF A NON-PERIODIC OSCILLATING BOUNDARY VIA PERIODIC UNFOLDING
This paper deals with the homogenization of an elliptic model problem in a two-dimensional domain with non-periodic oscillating boundary by the method of periodic unfolding. For the non-periodic oscillations, a modulated unfolding is used. The L-2 convergence of the solutions and their fluxes are shown, under natural hypotheses on the domain
Islamic Law and Sustainable Development Goals
This study aims to analyze Sustainable Development Goals (SDGs) prescribed by United Nations Development Program (UNDP) under Islamic Law. This paper is qualitative method of research analyzing SDGs under verses of Holy Qur'an and traditions of Prophet Muhammad ď·ş. This study found that what SDGs ask member states to do has been prescribed in Holy Qur'an and Sunnah of Prophet Muhammad ď·ş way back 1400 years ago and demanded by Almighty Allah and the last Prophet Muhammad ď·ş for eradication of poverty, hunger, malnutrition etc. Islamic law prohibits usury, gambling, uncertainty and other illegal activities to protect poor people of the society against rich landlords. Therefore, member states are required to follow SDGs to achieve peace, harmony and economic growth for betterment of humanity which is also a duty under verses of Holy Qur'an and traditions of Prophet Muhammad ď·ş to achieve success in this world and in the hereafter
Recovery of Xanthan Gum from Palm Oil-Based Fermentation Broth by Diafiltration with Flat Polysulfone Microfiltration (MF) Membrane
Xanthan gum recovery from palm oil-based broth by diafiltration was carried out using flat microfiltration (MF) membrane. Optimization of process parameters such as transmembrane pressure (TMP), crossflow velocity (CFV), ionic strength (IS) and diafiltration factor (DF) was performed by Taguchi method using signal-to-noise (S/N) ratio of larger-the-better criterion yielding the following optimum conditions: level 1, level 2, level 3, and level 2, respectively, corresponding to Xanthan recovery of 68 %. Analysis of variance (ANOVA) showed the significance of TMP on providing a driving force for Xanthan’s transmembrane transport (XTT), whereas little effect of DF indicated the evidence of sieving action by cake layer on XTT, which was also responsible for complete rejection of oil indicated by the absence of fatty acid component in permeate upon GC-MS analysis. On the contrary, better XTT was observed during MF operation on zero-oil broth due to absence of oily cake layer rendering CFV more effective
Spatial and Temporal Evolution of Particle Migration in Gap-Graded Granular Soils: Insights from Experimental Observations
This study presents physical observations and insights into particle
migration characteristics throughout the suffusion process. Using a
purpose-built coaxial permeameter cell, suffusion experiments were conducted on
idealised internally unstable gap-graded granular soils at varying fines
content and hydraulic loading conditions. The specimens were prepared with a
mixture layer comprising finer and coarser fractions underlying a coarse layer
composed of the coarser fraction alone. This enabled the finer fraction within
the mixture layer to migrate through the coarse layer with upward seepage flow.
The local porosity profile along the specimen was determined using spatial time
domain reflectometry and an inversion algorithm, which enabled the development
of a novel field map of the difference in porosity from the initial condition.
This field map provided a visual guide of the spatial and temporal variation in
porosity and enabled particle migration internally within the specimen to be
quantitatively characterised from onset to progression to washout. The limiting
onset condition identified from the field map was shown to be comparable to
that obtained using conventional approaches, thereby providing strong
validation for the application of porosity-based field maps. As suffusion
progressed, the height of infiltrating finer particles into the coarse layer
increased linearly with time, while the overall rate of particle migration from
the mixture layer to the coarse layer evolved in a non-linear manner with the
rate of migration increasing as the specimen reached a complete mixture
condition, where the finer fraction infiltrated the entire coarse layer. The
attainment of a complete mixture condition was dependent on the fabric of the
gap-graded soil ... (see PDF for full abstract).Comment: 28 pages, 20 figures. Article published in Journal of Geotechnical
and Geoenvironmental Engineering 2023 (see
https://ascelibrary.org/doi/10.1061/JGGEFK.GTENG-11094
Therapeutic anticoagulation complications in the elderly: a case report
Background: The demographic transition leads to a continuously growing number of elderly patients who receive therapeutic anticoagulation by reason of several comorbidities. Though therapeutic anticoagulation may reduce the number of embolic complications in these patients, major complications such as bleeding complications need to be kept in mind when considering such therapy. However, evidence regarding the choice of anticoagulation agents in chronic kidney disease patients of higher age is limited. In this report, a guideline-based anticoagulation treatment which led to a fulminant atraumatic bleeding complication is discussed.
Case presentation: We present the case of an 85-year-old female stage V chronic kidney disease patient who suffered from a diffuse arterial, subcutaneous bleeding in her lower left leg due a therapeutic anticoagulation using low molecular weight heparin (LMWH). Anticoagulation was started in accordance with general recommendations for patients with atrial fibrillation, and the dosage was adapted for the patient's renal function. Nevertheless, the above-mentioned complication occurred, and the bleeding led to a hemorrhagic shock and an acute kidney injury on top of a chronic kidney disease. The hematoma required surgical evacuation and local coagulation in the operating room. In the further course, the patient underwent additional four surgical interventions due to a superinfected skin necrosis, including skin grafting. Furthermore, the patient needed continuous renal replacement therapy, as well as intensive care unit treatment, for a total of 47 days followed by 36 days of geriatric rehabilitation. Afterwards, she was discharged from the hospital to her previous nursing home.
Discussion and conclusions: Although therapeutic anticoagulation may sufficiently protect patients at cardiovascular risk, major complications such as bleeding complications may occur at any time. Therefore, physicians need to regularly re-evaluate any prior indication for therapeutic anticoagulation. With this case report, we hope to draw attention to the cohort of geriatric patients and the need for more and well differentiated study settings to preferably prevent any potentially avoidable complications
Comparing Perioperative Outcome Measures of the Dynamic Hip Screw and the Femoral Neck System
Background and Objective: Various fixation devices and surgical techniques are available for the management of proximal femur fractures. Recently, the femoral neck system (FNS) was introduced, and was promoted on the basis of less invasiveness, shorter operating time, and less fluoroscopy time compared to previous systems. The aim of this study was to compare two systems for the internal fixation of femoral neck fractures (FNF), namely the dynamic hip screw (DHS) with an anti-rotation screw (ARS) and an FNS. The outcome measures included operating room time (ORT), dose–area product (DAP), length of stay (LOS), perioperative changes in haemoglobin concentrations, and transfusion rate. Materials and Methods: A retrospective single-centre study was conducted. Patients treated for FNF between 1 January 2020 and 30 September 2021 were included, provided that they had undergone closed reduction and internal fixation. We measured the centrum-collum-diaphyseal (CCD) and the Pauwels angle preoperatively and one week postoperatively. Results: In total, 31 patients (16 females), with a mean age of 62.81 ± 15.05 years, were included. Fracture complexity assessed by the Pauwels and Garden classification did not differ between groups preoperatively. Nonetheless, the ORT (54 ± 26.1 min vs. 91.68 ± 23.96 min, p < 0.01) and DAP (721 ± 270.6 cGycm² vs. 1604 ± 1178 cGycm², p = 0.03) were significantly lower in the FNS group. The pre- and postoperative CCD and Pauwels angles did not differ statistically between groups. Perioperative haemoglobin concentration changes (–1.77 ± 1.19 g/dl vs. –1.74 ± 1.37 g/dl) and LOS (8 ± 5.27 days vs. 7.35 ± 3.43 days) were not statistically different. Conclusions: In this cohort, the ORT and DAP were almost halved in the patient group treated with FNS. This may confer a reduction in secondary risks related to surgery
Collagen wrapping and local platelet-rich fibrin do not improve the survival rates of ACL repair with dynamic intraligamentary stabilization: a retrospective case series after ≥5 years postoperatively.
PURPOSE
Anterior cruciate ligament (ACL) repair has been recommended as a treatment principle for ACL tears. Several authors have advocated a potential role for primary repair techniques in the ACL decision tree. However, long-term results have been controversial. This study aims to determine the survival of the primarily repaired ACL after dynamic intraligamentary stabilization (DIS) with and without augmentation.
METHODS
Between 2014 and 2019, 102 patients with isolated proximal ACL ruptures underwent DIS repair within 21 days from injury and were available for follow-up either clinically or telephonically after ≥5 years postoperatively. In 45 cases, DIS repair was augmented with collagen fleece wrapping, platelet-rich fibrin (PRF) or both. Failure was defined as traumatic re-rupture or conversion to ACL reconstruction. The patients being available for physical examination underwent a.-p. stability measurement with a KT-1000 device. Functional outcome was measured with the IKDC, Tegner and Lysholm scores. Kaplan-Meier survival analysis, Log-Rank Test and Binominal logistic regression were performed.
RESULTS
After a minimum 5-year follow-up, 71/102 (69.6%) DIS repairs were not re-reptured and clinically and/or subjectively stable. Augmentation did not improve survival rates (p = 0.812). The identified factors influencing failure were a younger age and a pre-injury Tegner activity level of ≥7. 95.7% of those patients with an intact ACL repair had normal or near normal knee function based on the IKDC scoring system.
CONCLUSIONS
The 5-year overall survival rate of DIS was 69.6%. Collagen fleece wrapping and local PRF application did not improve survival. Patients not suffering failure of repair demonstrated high satisfaction. Nevertheless, the results are inferior to those of established ACL reconstruction procedures.
LEVEL OF EVIDENCE
Case series, Level IV
Outcome Analysis of the Use of Cerament® in Patients with Chronic Osteomyelitis and Corticomedullary Defects
Background: Chronic osteomyelitis (OM) is a progressive but mostly low-grade infection of the bones. The management of this disease is highly challenging for physicians. Despite systematic treatment approaches, recurrence rates are high. Further, functional and patient-reported outcome data are lacking, especially after osseous defects are filled with bioresorbable antibiotic carriers.
Objective: To assess functional and patient-reported outcome measures (PROM) following the administration of Cerament (R) G or V due to corticomedullary defects in chronic OM.
Methods: We conducted a retrospective study from 2015 to 2020, including all patients who received Cerament (R) for the aforementioned reason. Patients were diagnosed and treated in accordance with globally valid recommendations, and corticomedullary defects were filled with Cerament (R) G or V, depending on the expected germ spectrum. Patients were systematically followed up, and outcome measures were collected during outpatient clinic visits.
Results: Twenty patients with Cierny and Mader type III OM were included in this study and followed up for 20.2 +/- 17.2 months (95%CI 12.1-28.3). Ten of these patients needed at least one revision (2.0 +/- 1.3 revisions per patient (95%CI 1.1-2.9) during the study period due to OM persistence or local wound complications. There were no statistically significant differences in functional scores or PROMs between groups.
Conclusion: The use of Cerament (R) G and V in chronic OM patients with corticomedullary defects appears to have good functional outcomes and satisfactory PROMs. However, the observed rate of local wound complications and the OM persistence rate may be higher when compared to previously published data
The ischiofemoral space of the hip is influenced by the frontal knee alignment
Purpose: The ischiofemoral distance (IFD), defined as the distance between the ischial tuberosity and the lesser trochanter of the femur, is gaining recognition as an extra-articular cause of hip pain. It is unknown whether the IFD is influenced by the frontal knee alignment. The aim of this study was to determine the influence of realignment surgery around the knee on the IFD. It was hypothesized that valgisation osteotomy around the knee is associated with reduction of the IFD.
Methods: A consecutive series of 154 patients undergoing frontal realignment procedures around the knee in 2017 were included in this study. Long-leg standing radiographs were obtained before surgery and postoperatively. The IFD was measured between the ischium and the lesser trochanter at three different levels (proximal, middle and distal margins of the lesser trochanter parallel to the horizontal orientation of the pelvis) on standardized long-leg radiographs with the patient in upright standing position. The knee alignment was determined by measuring the hip knee ankle angle, mechanical lateral distal femur angle and the medial mechanical proximal tibia angle. Linear regression was performed to determine the influence of the change of frontal knee alignment on the IFD.
Results: Linear regression showed a direct influence of the overall change in frontal knee alignment on the IFD of the hip, regardless of the site of the osteotomy (beta-0.4, confidence-interval - 0.5 to - 0.3, p < 0.001). Valgisation osteotomy around the knee induced a significant reduction of the ipsilateral IFD (p < 0.001), while varisation osteotomy induced a significant increase (p < 0.001). The amount of ISD change was 0.4 mm per corresponding degree of change in frontal knee alignment.
Conclusion: These findings are relevant to both the hip and knee surgeons when planning an osteotomy or arthroplasty procedure. Correction of a malalignment of the knee may resolve an ischiofemoral conflict in the hip. The concept deserves inclusion in the diagnostic workup of both the hip and knee joints
- …