Temperature Prediction Using Multivariate Time Series Deep Learning in the Lining of an Electric Arc Furnace for Ferronickel Production.

The analysis of data from sensors in structures subjected to extreme conditions such as the ones used in smelting processes is a great decision tool that allows knowing the behavior of the structure under different operational conditions. In this industry, the furnaces and the different elements are fully instrumented, including sensors to measure variables such as temperature, pressure, level, flow, power, electrode positions, among others. From the point of view of engineering and data analytics, this quantity of data presents an opportunity to understand the operation of the system under normal conditions or to explore new ways of operation by using information from models provided by using deep learning approaches. Although some approaches have been developed with application to this industry, it is still an open research area. As a contribution, this paper presents an applied deep learning temperature prediction model for a 75 MW electric arc furnace, which is used for ferronickel production. In general, the methodology proposed considers two steps: first, a data cleaning process to increase the quality of the data, eliminating both redundant information as well as atypical and unusual data, and second, a multivariate time series deep learning model to predict the temperatures in the furnace lining. The developed deep learning model is a sequential one based on GRU (gated recurrent unit) layer plus a dense layer. The GRU + Dense model achieved an average root mean square error (RMSE) of 1.19 °C in the test set of 16 different thermocouples radially distributed on the furnace.

Development of a group contribution method for estimating free energy of peptides in a dodecane-water system via molecular dynamic simulations.

BACKGROUND: Calculation of the Gibbs free energy changes of biological molecules at the oil-water interface is commonly performed with Molecular Dynamics simulations (MD). It is a process that could be performed repeatedly in order to find some molecules of high stability in this medium. Here, an alternative method of calculation has been proposed: a group contribution method (GCM) for peptides based on MD of the twenty classic amino acids to obtain free energy change during the insertion of any peptide chain in water-dodecane interfaces. Multiple MD of the twenty classic amino acids located at the interface of rectangular simulation boxes with a dodecane-water medium were performed. RESULTS: A GCM to calculate the free energy of entire peptides is then proposed. The method uses the summation of the Gibbs free energy of each amino acid adjusted in function of its presence or absence in the chain as well as its hydrophobic characteristics. CONCLUSION: Validation of the equation was performed with twenty-one peptides all simulated using MD in dodecane-water rectangular boxes in previous work, obtaining an average relative error of 16%.

Therapeutic outcomes of endoscopic submucosal dissection of differentiated early gastric cancer in a Western endoscopy setting (with video).

BACKGROUND: Large multicenter gastric cancer endoscopic submucosal dissection (ESD) studies conducted at major Japanese institutions have reported en bloc resection, en bloc tumor-free margin resection, and curative resection rates of 92.7% to 96.1%, 82.6% to 94.5%, and 73.6% to 85.4%, respectively, with delayed bleeding and perforation rates of 0.6% to 6.0% and 3.6% to 4.7%, respectively. Although ESD is currently an alternative treatment in some countries, particularly in Asia, it remains uncertain whether ESD therapeutic outcomes in Western endoscopy settings can be comparable to those achieved in Japan. OBJECTIVE: To evaluate the ESD therapeutic outcomes for differentiated early gastric cancer (EGC) in a Western endoscopy setting. DESIGN/SETTING: Consecutive case series performed by an expertly trained Western endoscopist. PATIENTS: Fifty-three patients with 54 lesions. INTERVENTIONS: ESD for early gastric cancers (T1) satisfying expanded inclusion criteria. MAIN OUTCOME MEASUREMENTS: En bloc resection, en bloc tumor-free margin resection, and curative resection rates were 98%, 93%, and 83%, respectively. The delayed bleeding rate was 7%, and the perforation rate was 4%. RESULTS: The mean patient age was 67 years, and the mean tumor size was 19.8 mm, with 54% of the lesions located in the lesser curvature. The median procedure time was 61 minutes, with ESD procedures 60 minutes or longer associated with submucosal fibrosis (P < .001) and tumor size 25 mm or larger (P = .03). In every ESD procedure, both circumferential incision and submucosal dissection were performed by using a single knife. Two of the 4 delayed bleeding cases required surgery, and all perforations were successfully managed by using endoscopic clips. LIMITATION: Long-term outcome data are currently unavailable. CONCLUSION: ESD for differentiated EGC resulted in favorable therapeutic outcomes in a Western endoscopy setting comparable to those achieved at major Japanese institutions.

The evolution of laparoscopy in abdominal surgery: a meta-analysis of the effect on infectious outcomes.

BACKGROUND: Laparoscopic surgery has been recommended as an effective strategy because of its advantages in decreasing abdominal surgical site infections (SSIs). The aim of this study was to assess the effect of laparoscopy on superficial and organ/space SSIs compared with open surgery in hollow-viscus procedures over time. STUDY DESIGN: Data on SSIs from randomized-controlled trials (RCTs) evaluating open versus laparoscopic abdominal surgeries were extracted from the Cochrane Database Reviews. Re-analysis of these data was performed to assess infections. Heterogeneity was also explored. A subgroup analysis was performed according to elective/emergency surgery status. RESULTS: Data from 72 RCTs including 8218 patients were collected (4116 patients in the laparoscopic group and 4102 patients in the open group). For superficial SSI, the pooled RD was -4.4% (95% CI: -5.4% to -3.3%), which indicated a lower risk in the laparoscopic group. For organ/space SSI, the pooled RD was 0.5% (95% CI: -0.1% to 1%), which indicated similar rates between the groups. Changes in SSI frequency had occurred over time. CONCLUSION: Laparoscopic surgery significantly decreases the risk of superficial SSI but does not affect the risk of organ/space SSI. Experience with technique improves outcomes.

Adjacent Segment Disease After Spinal Fusion.

¼ Adjacent segment disease is characterized by a degenerative process adjacent to a previously fused spine segment, with new onset of clinical symptoms such as radiculopathy, myelopathy, or instability.¼ Etiology is related to the natural history of the disease process, increased biomechanical stress at adjacent segments, clinical factors specific to the individual patient, intraoperative factors, and malalignment.¼ Treatment is usually nonoperative, but surgical intervention can be indicated. Decompression and fusion remain the mainstay of operative treatment, and isolated decompression should be considered in specific cases.¼ Further randomized controlled trials are needed to establish how the treatment should progress, particularly with the development of minimally invasive and endoscopic surgery.

Complications of Lateral Decubitus Positioning During Orthopaedic Surgery.

¼ Lateral decubitus positioning is a nonanatomical position used for multiple orthopaedic procedures to obtain adequate surgical exposure.¼ Unique ophthalmologic, musculoskeletal, neurovascular, and hemodynamic complications may arise inadvertently from positioning.¼ Orthopaedic surgeons should be aware of the possible complications that may manifest from placing patients in the lateral decubitus position to adequately prevent and to properly manage them.

Robotic Spine Surgery in Rhode Island.

Surgical robots were first proposed in the 1960s with subsequent development and clinical implementation in the 1980s and 1990s. Recent advances in technology have led to widespread utilization of robots in many surgical subspecialties. In spine surgery, robots are primarily utilized for pedicle screw placement, with several studies highlighting the potential benefits of improved accuracy and reduction in radiation exposure. Once streamlined, robotic spine surgery (RSS) can provide financial renumeration through potential cost savings and marketing benefits, and in the future will likely aid in more complex surgeries. In Rhode Island, this technology has been implemented and has the potential to deliver optimized outcomes for patients. Robotic spine surgery is not a substitute for a skilled spine surgeon however, and careful diagnosis, care planning, and surgical execution are still mandatory to deliver the best possible patient outcomes. In this review, we chronicle the history of RSS, outline currently available RSS platforms, describe the efficacy, risks, and complications of RSS procedures, and explain the current and future utilization of RSS in Rhode Island.

Utilization of Antibiotic Bone Cement in Spine Surgery: Pearls, Techniques, and Case Review.

Vertebral osteomyelitis (VO) encompasses a spectrum of spinal infections ranging from isolated mild vertebral osteomyelitis to severe diffuse infection with associated epidural abscess and fracture. Although patients can often be treated with an initial course of intravenous antibiotics, surgery is sometimes required in patients with sepsis, spinal instability, neurological compromise, or failed medical treatment. Antibiotic bone cement (ABC) has been widely used in orthopedic extremity surgery for more than 150 years, both for prophylaxis and treatment of bacterial infection. However, relatively little literature exists regarding its utilization in spine surgery. This article describes ABC utilization in orthopedic surgery and explains the technique of ABC utilization in spine surgery. Surgeons can choose from multiple premixed ABCs with variable viscosities, setting times, and antibiotics or can mix in antibiotics to bone cements themselves. ABC can be used to fill large defects in the vertebral body or disc space or in some cases to coat instrumentation. Surgeons should be wary of complications such as ABC extravasation as well as an increased difficulty with revision. With a thorough understanding of the properties of the cement and the methods of delivery, ABC is a powerful adjunct in the treatment of spinal infections.

Bowel and Bladder Care in Patients With Spinal Cord Injury.

Complete and incomplete spinal cord injuries affect between 250,000 and 500,000 people on an annual basis worldwide. In addition to sensory and motor dysfunction, spinal cord injury patients also suffer from associated conditions such as neurogenic bowel and bladder dysfunction. The degree of dysfunction varies on the level, degree, and type of spinal cord injury that occurs. In addition to the acute surgical treatment of these patients, spine surgeons should understand how to manage neurogenic bowel and bladder care on both a short- and long-term basis to minimize the risk for complications and optimize potential for rehabilitation.

Development of a Robotic Spine Surgery Program: Rationale, Strategy, Challenges, and Monitoring of Outcomes After Implementation.

ABSTRACT: Surgical robots were invented in the 1980s, and since then, robotic-assisted surgery has become commonplace. In the field of spine surgery, robotic assistance is utilized mainly to place pedicle screws, and multiple studies have demonstrated that robots can increase the accuracy of screw placement and reduce radiation exposure to the patient and the surgeon. However, this may be at the cost of longer operative times, complications, and the risk of errors in mapping the patient's anatomy.

Antibiotic Cement Utilization for the Prophylaxis and Treatment of Infections in Spine Surgery: Basic Science Principles and Rationale for Clinical Use.

Antibiotic bone cement (ABC) is an effective tool for the prophylaxis and treatment of osteomyelitis due to the controlled, sustained release of local antibiotics. ABC has been proven to be effective in the orthopedic fields of arthroplasty and extremity trauma, but the adoption of ABC in spine surgery is limited. The characteristics of ABC make it an optimal solution for treating vertebral osteomyelitis (VO), a serious complication following spine surgery, typically caused by bacterial and sometimes fungal and parasitic pathogens. VO can be devastating, as infection can result in pathogenic biofilms on instrumentation that is dangerous to remove. New techniques, such as kyphoplasty and novel vertebroplasty methods, could amplify the potential of ABC in spine surgery. However, caution should be exercised when using ABC as there is some evidence of toxicity to patients and surgeons, antibiotic allergies, bone cement structural impairment, and possible development of antibiotic resistance. The purpose of this article is to describe the basic science of antibiotic cement utilization and review its usage in spine surgery.

Early laparoscopy for the evaluation of nonspecific abdominal pain: a critical appraisal of the evidence.

BACKGROUND: Patients with nonspecific abdominal pain (NSAP) are frequently seen in emergency departments. Different studies have suggested that early laparoscopy (EL) could be an adequate tool to accelerate diagnosis and therapy. The aim of this study was to assess the effectiveness of EL in terms of diagnosis, persistence of NSAP, mortality, morbidity, cost, hospital stay, and quality of life relative to observation in NSAP. METHODS: We performed a systematic review to identify randomized controlled trials (RTC) comparing EL versus active observation (AO) in NSAP. The primary outcomes were the number of patients with positive and negative findings, the utility for each group, and the cases with persistence of NSAP. Methodologic quality was assessed using the recommendations of the Cochrane Collaboration. RESULTS: Five studies that included a total of 921 patients were included: 460 in the EL group and 461 in the AO group. The use of an important methodologic heterogeneity between included studies avoided a pooled analysis. Data suggested that EL performed better in establishing a final diagnosis (79.2-96.9%) vs. AO (28.1-78.1%); however, the final therapeutic utility of laparoscopy was lower than the diagnostic rate (10.9-86.5%). The mortality rate of EL was similar to AO, and morbidity ranged from 1.15 to 23.72% in EL compared with the range from 1.9 to 31.14% in AO. The length of hospital stay ranged from 1.3 to 4.18 days in EL compared with the range from 2 to 7.3 days in AO. CONCLUSIONS: There is an important heterogeneity between the populations and in the degree of methodologic quality in the included studies. Data suggest that EL performs better in establishing a final diagnosis after admission, but the lack of uniform information does not allow for the recommendation of EL as a routine strategy in clinical practice. We recommend that a large trial be conducted with specific operative characteristics to solve problems identified in primary trials.

Nosocomial COVID-19 infection mortality following surgery for severe progressive cervical myelopathy: a case report.

INTRODUCTION: We present the unique case of a nosocomial COVID infection acquired after urgent surgical intervention for cervical myelopathy, as well as the sequelae that followed in the postoperative period. CASE PRESENTATION: An initially COVID-negative patient underwent urgent surgical intervention for cervical myelopathy with significant neurological deterioration. She underwent an uncomplicated staged anterior cervical discectomy and fusion with corpectomy, as well as a subsequent posterior cervical instrumented fusion within the same hospitalization. The patient would refuse to adhere to standard COVID precautions during her admission and demonstrated rapid decompensation following her particularly uneventful surgeries, ultimately leading to her expiration. A laboratory test confirmed that she had contracted COVID at the time of the patient's death. DISCUSSION: This report highlights the repercussions of COVID-19 infection during the perioperative period and its implications on surgical outcomes. The stresses of surgery and the body's immunosuppressive responses during this time place patients at particular risk for the contraction of this virus. The standard precautions should be followed and vaccination should be considered for surgical candidates prior to their operations, as they become more readily accessible.

[Impact of the flipped classroom strategy in the learning environment in surgery: A comparison with the lectures]. / Impacto de la estrategia de aula invertida en el ambiente de aprendizaje en cirugía: una comparación con la clase magistral.

INTRODUCTION: The Facultad de Medicina of the Universidad de La Sabana routinely uses lectures as the major educational strategy in clinical areas. Since 2012, a curriculum in context and a flipped classroom were introduced in the surgery course. OBJECTIVE: To compare the impact of lectures versus the flipped classroom model in the learning environment in surgery. MATERIALS AND METHODS: The Dundee Ready Education Environment Measure (DREEM) questionnaire was administered to four cohorts of students. The five domains and the overall scores for both strategies were analyzed, and ANOVA was used to determine the differences among the domains (p<0.05). The internal consistency was assessed using Cronbach´s alpha coefficient. RESULTS: There were 207 participants (men: 36%) that completed the questionnaire (age: 21.9 ± 1.49 years old). The overall DREEM score and the subscales were higher with the flipped classroom, which suggests that this environment had a higher level of excellence. The ANOVA for each domain and the overall scores showed no differences with a flipped classroom. However, significant differences were identified in all domains and the overall scores with lectures (p<0.01). There were high levels of reliability (Cronbach>0.90) for all measurements in both environments, and there was consistency across all cohorts. CONCLUSIONS: The flipped classroom strategy showed a higher score than the lecture-based approach according to the DREEM questionnaire. Identifying factors with a negative score is crucial to improving the learning environment. It is necessary to conduct further measurements over time to ensure the quality and success of the strategy.

Prediction of prolonged mechanical ventilation in patients in the intensive care unit A cohort study.

INTRODUCTION: There are no established guidelines for selecting patients for early tracheostomy. The aim was to determine the factors that could predict the possibility of intubation longer than 7 days in critically ill adult patients. METHODS: This is cohort study made at a general intensive care unit. Patients who required at least 48 hours of mechanical ventilation were included. Data on the clinical and physiologic features were collected for every intubated patient on the third day. Uni- and multivariate statistical analyses were conducted to determine the variables associated with extubation. RESULTS: 163 (62%) were male, and the median age was 59±17 years. Almost one-third (36%) of patients required mechanical ventilation longer than 7 days. The variables strongly associated with prolonged mechanical ventilation were: age (HR 0.97 (95% CI 0.96-0.99); diagnosis of surgical emergency in a patient with a medical condition (HR 3.68 (95% CI 1.62-8.35), diagnosis of surgical condition-non emergency (HR 8.17 (95% CI 2.12-31.3); diagnosis of non-surgical-medical condition (HR 5.26 (95% CI 1.85-14.9); APACHE II (HR 0.91 (95% CI 0.85-0.97) and SAPS II score (HR 1.04 (95% CI 1.00-1.09) The area under ROC curve used for prediction was 0.52. 16% of patients were extubated after day 8 of intubation. CONCLUSIONS: It was not possible to predict early extubation in critically ill adult patients with invasive mechanical ventilation with common clinical scales used at the ICU. However, the probability of successfully weaning patients from mechanical ventilation without a tracheostomy is low after the eighth day of intubation.

INTRODUCCIÓN: No existen guías establecidas para seleccionar los pacientes para traqueostomía precoz. El objetivo del estudio fue determinar los factores que pueden predecir la posibilidad de intubación mayor a 7 días en pacientes adultos en la UCI. MÉTODOS: Este es un estudio de cohorte realizado en la UCI. Los pacientes en ventilación mecánica mayor a 48 horas fueron incluidos. Se recogieron los datos clínicos y fisiológicos de cada paciente al tercer día de intubación. Se realizaron análisis uní y multivariado para determinar las variables asociadas a intubación prolongada. RESULTADOS: 163 (62%) fueron hombres y la edad media fue de 59±17 años. Aproximadamente un tercio de los pacientes (36%) requirieron ventilación mecánica mayor a 7 días. Las variables asociadas con ventilación mecánica prolongada fueron: edad (HR 0.97 (95% CI 0.96-0.99); diagnóstico de urgencia quirúrgica en un paciente con enfermedad médica (HR 3.68 (95% CI 1.62-8.35),diagnostico de necesidad de cirugía no urgente (HR 8.17 (95% CI 2.12-31.3); diagnóstico de enfermedad medica no quirúrgica (HR 5.26 (95% CI 1.85-14.9); APACHE II (HR 0.91 (95% CI 0.85-0.97) y puntaje SAPS II (HR 1.04 (95% CI 1.00-1.09). El área bajo la curva ROC para predicción fue de 0.52. 16% de los pacientes fueron extubados después de 8 días de intubación. CONCLUSIONES: No fue posible predecir la extubation precoz en pacientes de la unidad de cuidado intensivo en ventilación mecánica con las variables comúnmente usadas. La probabilidad de destete de ventilación mecánica después de 8 días de intubación sin realizar traqueostomía es baja.

Prognosis of patients with thyroid cancer who do not undergo surgical treatment: a SEER database analysis.

BACKGROUND: The treatment for thyroid cancer is surgical. However, some patients do not undergo operations because of comorbidities or other reasons. There is little information about the prognosis of these patients. The aim of the present study was to describe patients with well differentiated thyroid carcinoma who did not undergo surgical treatment and to identify differences in prognostic variables and survival compared with patients treated surgically. METHODS: We conducted a retrospective review of a prospective cohort collected by the National Cancer Institute obtained from the Surveillance, Epidemiology and End Results (SEER) Program. All patient files with a diagnosis of thyroid cancer were selected (38,493 cases). Finally, 12,416 cases were used for the analysis. Treatment was divided into surgical or nonsurgical groups. Five-year survival rates were estimated and classified by the SEER stage. RESULTS: Eighty-six patients did not receive surgical treatment. These patients were older, had more advanced tumours and their treatment was less associated with complementary radiotherapy. Five-year overall survival rates were 96.7% for surgical patients vs. 56.8% for nonsurgical patients (p<0.001). The overall survival in the nonsurgery group for localised tumours decreased 14.9%, for regional tumours decreased 49.9% and for distant tumours decreased 61.8%. DISCUSSION: The patients who did not undergo surgical treatment showed less than 5-year overall survival. The SEER database does not offer information about comorbidities that could explain these differences.

Routine postoperative administration of vitamin D and calcium after total thyroidectomy: a meta-analysis.

BACKGROUND: Temporary hypocalcemia is a frequent complication after total thyroidectomy. Routine postoperative administration of vitamin D and calcium can reduce the incidence of symptomatic postoperative hypocalcemia. We undertook a systematic review to assess the effectiveness of this intervention. METHODS: We identified randomized controlled trials comparing the administration of vitamin D or metabolites to oral calcium or no treatment in patients after total thyroidectomy in MEDLINE, EMBASE and LILACS databases. RESULTS: Four studies with 706 patients were included: 346 in the calcitriol group, 288 in the oral calcium group and 72 in the control group. The rates of hypocalcemia symptoms were 4%, 19% and 31%, respectively. The OR value for the comparison between calcitriol + calcium as compared to no treatment and to exclusive calcium treatment groups was 0.32 (95% CI, 0.13-0.79) and 0.31 (95% CI, 0.14-0.70), respectively. CONCLUSION: The prophylactic treatment with vitamin D or metabolites + calcium is effective to decrease the incidence of symptoms of temporary hypocalcemia.

Cost-effectiveness analysis regarding postoperative administration of vitamin-D and calcium after thyroidectomy to prevent hypocalcaemia.

OBJECTIVE: Hypocalcaemia is a frequently arising complication following total thyroidectomy. Routine postoperative prophylactic administration of vitamin D or metabolites and calcium reduce the incidence of symptomatic hypocalcaemia; this article reports evaluating its cost-effectiveness in Colombia. METHODS: Meta-analysis was used for comparing the administration of vitamin D or metabolites to oral calcium or no treatment at all in patients following total thyroidectomy and a cost-effectiveness analysis was designed based on a decision-tree model with local costs. RESULTS: The OR value for the comparison between calcitriol and calcium compared to no treatment and to exclusive calcium treatment groups was 0.32 (0.13-0.79 95 %CI) and 0.31 (0.14-0.70 95 %CI), respectively. The most cost-effective strategy was vitamin D or metabolites and calcium administration, having a US $0.05 incremental cost-effectiveness ratio. CONCLUSION: Prophylactic treatment of hypocalcaemia with vitamin D or metabolites + calcium or calcium alone is a cost-effective strategy.