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The current status information on producing high entropy alloys with laser-powder bed fusion (L-PBF).Identifying the stages of development in the studies.Presenting evaluations of the importance of the conducted studies.The importance of parameters used in L-PBF methods.Recommendations for key areas of focus for future work.

Due to the philosophy of the process, the surface roughness is usually high for the parts produced with laser powder bed fusion (L-PBF) additive manufacturing (AM). Parts produced by this method need surface quality improvement processes for many applications. One of the methods used for this purpose is high speed machining (HSM). HSM is a modern manufacturing technique that offers several benefits, including improved productivity, enhanced product quality, and reduced production costs. In addition, HSM can improve the quality of finished products by reducing machining errors. In this study, samples produced with 316L powder in size of 10 × 10 × 5 mm using three different hatch spacings (60, 70, 80 µm) and building orientations (0°, 45°, 90°) were produced by L-PBF method, and HSM process was applied to these samples. In this context, the present study aimed to investigate the effects of porosity, microstructure and microhardness properties of 316L samples produced by L-PBF method using different hatch spacings and build orientations on cutting forces, surface roughness and burr formation in HSM. When the numerical values of the cutting forces were analyzed in both xand ydirections, it was observed that the greatest cutting force occurred in the xdirection. While the Fx force ranged from 6.23 to 9.35 N, the Fy force ranged from 4.88 to 8.27 N. It has been determined that as the build orientation increases at the same hatch spacing value, the cutting forces increase due to the increased porosity ratio.

Background: This retrospective study compares tibial component rotations and radiological and functional outcomes in patients who underwent Oxford medial unicompartmental knee arthroplasty (UKA), using the antero-posterior (AP) tibia axis or anterior superior iliac spine (ASIS) as the landmarks for the direction of the vertical cut. Methods: A total of 86 patients, who underwent Oxford medial UKA were divided into 2 groups, each consisting of 43 patients, according to the use of AP axis (group I) or ASIS (group II) as landmarks for the rotation of vertical tibial cut and compared for the radiological and functional outcomes. Tibial component rotations (α-angle), involvement of the posterior cruciate ligament (PCL) fossa, and instant bearing position (IBP) were measured on computed tomography (CT) images. Functional outcomes were evaluated using Oxford knee score (OKS) and Knee Society score (KSS). Result: The median α‑angle was significantly smaller in group I than group II (2.5°, range −4–5.5° vs. −6°, range −13–0.5°, p< 0.001). The rates of PCL fossa involvements were 14 (32.6%) and 17 (39.5%, p= 0.7). The median flexion angle of the femoral component (7° vs. 10.5°) and posterior tibial slope (6° vs. 8°) were significantly lower in group I than group II (p= 0.001). All other radiological parameters, preoperative and final OKS and KSS were statistically similar in both groups. Conclusion: Taking the AP tibial axis as a landmark for vertical tibial cut rotation provides more neutral tibial component rotation in Oxford medial UKA compared to ASIS; however, this difference may not influence the clinical outcomes.

Purpose: Two-surgeon, simultaneous bilateral total knee arthroplasty (TKA) is considered as an unpredictable, complex procedure in terms of its radiographic and functional outcomes because of different surgeons and teams, and too many instruments and hands in a narrow space. We compared radiological and functional results of simultaneous bilateral TKA and single-surgeon sequential bilateral TKA. Methods: The 136 participants with a minimum of 24 months follow-up were prospectively randomized into 2 groups: two-surgeon bilateral TKA and single-surgeon bilateral TKA. We prespecified primary outcome of the study as between-group differences in terms of component alignment in the coronal and sagittal planes. Short-term functional outcomes were evaluated prospectively using the Oxford Knee Score (OKS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Results: Each group consisted of 136 knees of 68 patients. The mean tibial medial angles (TMA) were 89° ± 3 ° and 88° ± 5° in two-surgeons and single surgeon groups, respectively (p= 0.24). Radiological outcomes showed that the mean femoral lateral angles (FLA) were 87.9 ± 3.5° and 85.84 ± 3.7° (p= 0.12), posterior tibial slope angles (PTSA) were 8.2 ± 16.9° and 7.6 ± 17.8° (p= 0.84), and femoral flexion angles (FFA)were 86.8 ± 3.8° and 86.3 ± 3.5° (p= 0.41), anterior femoral offset ratios (AFOR) (%) were 29.5 ± 11.1 and 27.7 ± 7.9 (p= 0.31), and posterior femoral offset ratio (PFOR) (%) were 108.41 ± 31.3 and 108.45 ± 25.7 (p= 0.98), respectively. Conclusion: Two-team simultaneous bilateral TKA is as safe as single stage one-surgeon sequential bilateral TKA in terms of short-term component radiological and the functional outcomes.

Background: This study compared internal fixation with a plate after lengthening (PAL) with an external fixator with the conventional method (CM) in terms of radiologic and clinical outcomes in the lower extremities of patients with achondroplasia. Methods: In this study 20 patients (50 lower extremity long bones) who underwent PAL or CM were divided into 2 cohort groups. The amount of lengthening, percentage lengthening, external fixator index (EFI), external fixator time, Li regeneration index, complication rate, and knee range of motion (ROM) were compared between the groups. Results: The median age was 9.4 years (range 6–16 years) in the PAL group and 12 years (range 9–16 years) in the CM group (p= 0.01). Males comprised 80% of the patients in the PAL group and 47% of the patients in the CM group (p= 0.02). The median amount of lengthening in the PAL and CM groups was 7.5 cm (range 5.5–9.5 cm) and 6.0 cm (range 5.5–9.0 cm), respectively (p< 0.01). The median percentage of lengthening in the PAL and CM groups was 44.6% (range 20.0–70.1%) and 43.0% (range 20.5–57.3%), respectively (p= 0.01). The median external fixator time in the PAL and CM groups was 127 days (range 94–185 days) and 180 days (range 105–355 days), respectively (p< 0.01). The median EFI in the PAL and CM groups was 21 days/cm (range 10–33 days/cm) and 27 days/cm (range 15–59 days/cm), respectively (p< 0.01). The Li regeneration index was 3 (interquartile range, IQR 2–4) in both groups (p= 0.2). The total complication rate was similar between the groups. Conclusion: In patients with achondroplasia, after lengthening with an external fixator, internal fixation with a plate can be a reliable alternative to the conventional method. Level of evidence: Level III therapeutic

ABSTRACTObjectiveWe aimed to investigate the roles of inflammatory parameters, including neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), lymphocyte/monocyte ratio (LMR), and C-reactive protein/albumin ratio (CAR), in predicting disease recurrence in patients with stage IIA (T3N0M0) high microsatellite instability and microsatellite-stable colon cancer who had no risk factors associated with relapse.Materials and methodsWe evaluated 155 patients with colon cancer followed in 3 hospitals in Turkey between February 2009 and March 2020. These patients had stage IIA disease and had no risk factors associated with relapse. None of the patients received adjuvant chemotherapy. NLR, PLR, LMR, and CAR parameters were retrospectively obtained from laboratory results at the time of diagnosis, and their associations with disease recurrence were assessed.ResultsOver a median follow-up period of 38 months (range: 4–98 months), 11 of the 155 patients experienced relapse or developed metastases. Multivariate Cox analyses revealed that NLRs of ≥3.12 (hazard ratio [HR]: 0.041, 95% confidence interval [CI]: 0.048–0.826, p = 0.006) and CARs of ≥0.027 (HR: 0.199, 95% CI: 0.004–0.404, p = 0.026) were independent prognostic markers predicting relapse. The median 5-year recurrence-free survival rate of patients with NLRs of ≥3.12 at the time of diagnosis was 88.0%; this rate was 100% in patients with NLRs of <3.12 (p < 0.001). Similarly, the median 5-year recurrence-free survival rate of patients with CARs of ≥0.027 at the time of diagnosis was 84.7%; this rate was 95.7% in patients with CARs of <0.027 (p = 0.016).ConclusionIn this study, NLR and CAR were found to be independent prognostic markers predicting disease recurrence in patients with stage IIA colon cancer who did not receive adjuvant chemotherapy due to low clinical risk.

The aim of this cadaveric study was to investigate the efficacy of the modified Stoppa approach in Ganz periacetabular osteotomy (PAO).

This study aims to investigate the role of education in Turkish people living in Europe for the participation to labor market. Unemployment among approximately 5 million Turks living in European countries is above the average of countries where they live. While the percent of manufacturing sector in labor market decreased after the period of industry, the percent of sectors requiring qualified labor increased. As the demand for qualified labor increase, Turks being unqualified for the sectors employing qualified labor have to face with unemployment issue. A considerable part of Turks living in Europe being unqualified for the demands of labor market in information society and the education they receive being inadequate when confronted with unemployment is leading cause of this result. Every generation among Turks living in Europe has a better condition than the former one in terms of education. The successful ones in entrepreneurship by taking a good education and others enhancing their status by means of working in white collar occupations were seen. So, to be more successful in participation to the labor market and to have qualifications demanded by labor market changing structurally will be possible for Turks living in Europe with the help of receiving the same education as people whom they live together, studying in better schools and completing education process successfully

•Cooling performance and COP value of Peltier TE cooling systems is investigated.•Base thickness and airflow parameters are surveyed with a novel heat exchanger design.•The performance of TE refrigerators is low and their COP value decreases with operating time.•Cooling performance improved by increasing the fan velocity and decreasing base thickness.•The external fan velocity has a notable impact on the temperature drop of TE refrigerator.