Bioleaching of sewage sludge for copper extraction using Acidithiobacillus thiooxidans: Optimization and ecological risk assessment.

In this study, Acidithiobacillus thiooxidans was used for the bioleaching of copper (Cu) from sewage sludge. In order to find optimization conditions, three factors including solid-to-liquid ratio (S/L) (0.01-0.2 %(w/v)), initial element sulfur (S0) (1-10 g/L), and initial pH (1-3) have been investigated. Based on response surface methodology (RSM) determined a significant reduced quadratic model with a p-value of 0.0022 (<0.05 significant level). The maximum Cu recovery was 85.3% in the optimum condition of S/L = 0.16% (w/v), S0 = 8.2 g/L, and pH = 1.4. Furthermore, a kinetic study based on a shrinking core model was performed and the result showed that chemical reaction was rate limiting in the extraction. Toxicity Characteristic Leaching Procedure (TCLP) results after bioleaching showed the bioleaching process detoxified sludge and the bioleached sludge residue was well within the regulatory limits for disposal. The germination seed with adding bioleached and unbioleached sludge to the soil was determined. Various parameters such as Germination Index (GI), Tolerance Index (TI), Vigor Index (VI), and stem length showed that the sewage sludge indices significantly increased than the sample soil with unbioleached sludge.

Standardized videos in addition to the surgical curriculum in Medical Education for surgical clerkships: a cohort study.

BACKGROUND: Medical students are expected to translate the theoretical knowledge gained during their study to practical knowledge during the clerkships. A surgical educational platform with standardized videos may be the solution. However, the effects of a structured online video-based platform in addition to the standard curriculum on students' self-reported and tested surgical knowledge during the surgical clerkship must be assessed. METHODS: Fourth-year medical students (n = 178) participated in a 6-week course of theoretical and practical training followed by a 10-week in-hospital clerkship in the Erasmus University Medical Center (Erasmus MC), Rotterdam, The Netherlands and 11 affiliated general hospitals. Ninety students followed the usual surgical curriculum (control group), followed by 88 students who were given voluntary access to a video-based surgical educational platform of Incision Academy (video group). At the start (T0) and end (T1) of the clerkship, both groups filled out a surgical knowledge test and a survey regarding their self-reported surgical knowledge and their access to available study sources. Supervisors were blinded and surveyed concerning students' performance and their acquired knowledge. We analyzed the data using paired and unpaired student t-tests and linear regression. RESULTS: At the end of the clerkship, students in the video group indicated that they had better resources at their disposal than the control group for surgical procedures (p = 0.001). Furthermore, students in the video group showed a greater increase in self-reported surgical knowledge during their clerkship (p = 0.03) and in more objectively tested surgical knowledge (p < 0.001). CONCLUSIONS: An online surgical educational platform with standardized videos is a valuable addition to the current surgical curriculum according to students and their supervisors. It improves their test scores and self-reported surgical knowledge. Students feel better prepared and more able to find the information necessary to complete the clerkship. TRIAL REGISTRATION: Registry not necessary according to ICMJE guidelines.

Guidelines for Treatment of Umbilical and Epigastric Hernias From the European and Americas Hernia Societies-A Web-Based Survey on Surgeons' Opinion.

Background and aims: The European and Americas Hernia Society's (EHS and AHS) Guidelines on the treatment of primary midline ventral hernias were launched to guide surgeons. As a part of a dissemination plan of the guideline, this study aimed to evaluate the level of consensus between recommendations and the current surgical practices of EHS and AHS members before implementation. Material and methods: A questionnaire was constructed including questions on the current practice of the members and nine selected key recommendations from the guidelines. An on-stage consensus voting was performed at the EHS Congress in Hamburg 2019 followed by a SurveyMonkey sent to all EHS and AHS members. Consensus with a recommendation was defined as an agreement of ≥70%. Results: A total of 178 votes were collected in Hamburg. A further 499/1,754 (28.4%) of EHS and 150/1,100 (13.6%) of AHS members participated in the SurveyMonkey. A consensus was reached for 7/9 (78%) of the recommendations. The two recommendations that did not reach consensus were on indication and the technique used for laparoscopic repair. In current practice, more AHS participants used a preformed patch; 50.7% (76/150) compared with EHS participants 32.1% (160/499), p < 0.001. Conclusion: A consensus was achieved for most recommendations given by the new guideline for the treatment of umbilical and epigastric hernias. Recommendations that did not reach consensus were on indication and technique for laparoscopic repair, which may reflect the lack of evidence on these topics.

Learning inguinal hernia repair? A survey of current practice and of preferred methods of surgical residents.

PURPOSE: During surgical residency, many learning methods are available to learn an inguinal hernia repair (IHR). This study aimed to investigate which learning methods are most commonly used and which are perceived as most important by surgical residents for open and endoscopic IHR. METHODS: European general surgery residents were invited to participate in a 9-item web-based survey that inquired which of the learning methods were used (checking one or more of 13 options) and what their perceived importance was on a 5-point Likert scale (1 = completely not important to 5 = very important). RESULTS: In total, 323 residents participated. The five most commonly used learning methods for open and endoscopic IHR were apprenticeship style learning in the operation room (OR) (98% and 96%, respectively), textbooks (67% and 49%, respectively), lectures (50% and 44%, respectively), video-demonstrations (53% and 66%, respectively) and journal articles (54% and 54%, respectively). The three most important learning methods for the open and endoscopic IHR were participation in the OR [5.00 (5.00-5.00) and 5.00 (5.00-5.00), respectively], video-demonstrations [4.00 (4.00-5.00) and 4.00 (4.00-5.00), respectively], and hands-on hernia courses [4.00 (4.00-5.00) and 4.00 (4.00-5.00), respectively]. CONCLUSION: This study demonstrated a discrepancy between learning methods that are currently used by surgical residents to learn the open and endoscopic IHR and preferred learning methods. There is a need for more emphasis on practising before entering the OR. This would support surgical residents' training by first observing, then practising and finally performing the surgery in the OR.

Accuracy and usefulness in assessing proficiency of the observational clinical human reliability assessment checklist of the open inguinal hernia repair procedure: A cross-sectional study.

BACKGROUND: The Observational Clinical Human Reliability Assessment (OCHRA) can be used to score errors during surgical procedures. To construct an OCHRA-checklist, steps, substeps, and hazards of a surgical procedure need to be defined. A step-by-step framework was developed to segment surgical procedures into steps, substeps, and hazards. The first aim of this study was to investigate if the step-by-step framework could be used to construct an accurate Lichtenstein open inguinal hernia repair (LOIHR) stepwise description. The second aim was to investigate if the OCHRA-checklist based on this stepwise description was accurate and useful for surgical training and assessment. MATERIALS AND METHODS: Ten expert surgeons rated statements regarding the accuracy of the LOIHR stepwise description, the accuracy, and the usefulness of the LOIHR OCHRA-checklist (eight, seven, and six statements, respectively) using a 5-point Likert scale. One-sample Wilcoxon signed-rank test was used to compare the outcomes to the neutral value of 3. RESULTS: The accuracy of the stepwise description and the accuracy and usefulness of the OCHRA-checklist were rated statistically significantly higher than the neutral value of 3 (median 4.75 [5.00-4.00] with p = .009, median 5.00 [5.00-4.00] with p = .012, median 4.00 [5.00-4.00] with p = .047, respectively). The experts rated the OCHRA-checklist to be useful for the training (5.00 [5.00-4.00], p = .009), and assessment (4.50 [5.00-4.00], p = .010) of surgical residents. CONCLUSION: This preliminary study showed that the stepwise LOIHR description constructed using the step-by-step framework was found to be accurate. The LOIHR OCHRA-checklist developed using the stepwise description was also accurate, and particularly useful for the training and assessment of proficiency of surgical residents.

Validity of a low-cost Lichtenstein open inguinal hernia repair simulation model for surgical training.

PURPOSE: Simulation training allows trainees to gain experience in a safe environment. Computer simulation and animal models to practice a Lichtenstein open inguinal hernia repair (LOIHR) are available; however, a low-cost model is not. We constructed an inexpensive model using fabric, felt, and yarn that simulates the anatomy and hazards of the LOIHR. This study examined the fidelity, and perceived usefulness of our developed simulation model by surgical residents and expert surgeons. METHODS: A total of 66 Dutch surgical residents and ten international expert surgeons were included. All participants viewed a video-demonstration of LOIHR on the simulation model and subsequently performed the surgery themselves on the model. Afterward, they assessed the model by rating 13 statements concerning its fidelity (six model, three equipment, and four psychological) and six usefulness statements on a five-point Likert scale. One-sample Wilcoxon signed-rank test was used to compare to the neutral value of 3. RESULTS: The fidelity was assessed as being high by residents [model 4.00 (3.00-4.00), equipment 4.00 (3.00-4.00), psychological 4.00 (3.00-4.00); all p's < 0.001] and by expert surgeons [model 4.00 (3.00-4.00), p = 0.025; equipment 4.00 (3.00-5.00), p < 0.001; psychological 4.00 (3.00-4.00), p = 0.053]. The usefulness was rated high by residents and experts, especially the usefulness for training of residents [residents 4.00 (4.00-5.00), p < 0.001; experts 4.50 (3.75-5.00), p = 0.015]. CONCLUSION: Our developed Lichtenstein open inguinal hernia repair simulation model was assessed by surgical residents and expert surgeons as a model with high fidelity and high potential usefulness, especially for the training of surgical residents.

Creation of a universal language for surgical procedures using the step-by-step framework.

BACKGROUND: Learning of surgical procedures is traditionally based on a master-apprentice model. Segmenting procedures into steps is commonly used to achieve an efficient manner of learning. Existing methods of segmenting procedures into steps, however, are procedure-specific and not standardized, hampering their application across different specialties and thus worldwide uptake. The aim of this study was to establish consensus on the step-by-step framework for standardizing the segmentation of surgical procedures into steps. METHODS: An international expert panel consisting of general, gastrointestinal and oncological surgeons was approached to establish consensus on the preciseness, novelty, usefulness and applicability of the proposed step-by-step framework through a Delphi technique. All statements were rated on a five-point Likert scale. A statement was accepted when the lower confidence limit was 3·00 or more. Qualitative comments were requested when a score of 3 or less was given. RESULTS: In round one, 20 of 49 experts participated. Eighteen of 19 statements were accepted; the 'novelty' statement needed further exploration (mean 3·05, 95 per cent c.i. 2·45 to 3·65). Based on the qualitative comments of round one, five clarifying statements were formulated for more specific statements in round two. Twenty-two experts participated and accepted all statements. CONCLUSION: The international expert panel consisting of general, gastrointestinal and oncological surgeons supported the preciseness, usefulness and applicability of the step-by-step framework. This framework creates a universal language by standardizing the segmentation of surgical procedures into step-by-step descriptions based on anatomical structures, and may facilitate education, communication and assessment.

High prevalence of low bone mineral density in patients within 10 years of onset of ankylosing spondylitis: a systematic review.

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease. Decreased bone mineral density (BMD) is a common complication of AS, with a prevalence range of 19 to 62 %. Many studies have shown decreased BMD in AS with long disease duration, but only a few studies investigated BMD in early AS. The prevalence of decreased BMD in early disease stages of AS has not yet been clearly described, and for that reason, we reviewed the literature which describes the prevalence of decreased BMD in AS patients with a short disease duration (<10 years). In this review, we included articles which used the modified New York criteria for the diagnosis of AS, included patients with a disease duration of less than 10 years, and used the WHO criteria for osteopenia and osteoporosis. Decreased BMD was defined as a T score < -1.0, including both osteopenia and osteoporosis. For this review, only articles that acquired BMD data of lumbar spine and femoral neck by DXA were used. The literature search provided us 35 articles of which 7 matched all our criteria, and they will be further outlined in this review. The overall prevalence of decreased BMD of the articles reviewed is 54 % (n = 229/424) for lumbar spine and 51 % (n = 224/443) for femoral neck. The prevalence of osteopenia vs. osteoporosis for lumbar spine is 39 vs. 16 % and for femoral neck, 38 vs. 13 %. This review showed a high total prevalence of 51-54 % decreased BMD and 13-16 % osteoporosis in AS with a short disease duration. This high prevalence was not to be expected in a relatively young and predominantly male population. Further research is needed to determine the clinical relevance of this low BMD by investigating the relation between low BMD and vertebral and nonvertebral fractures at this early stage in AS.