Lactic acid Production with in situ Extraction in Membrane Bioreactor

Background and Objective: Lactic acid is widely used in the food, chemical and pharmaceutical industries. The major problems associated with lactic acid production are substrate and end-product inhibition, and by-product formation. Membrane technologyrepresents one of the most effective processes for lactic acid production. The aim of this work is to increase cell density and lactic acid productivity due to reduced inhibition effect of substrate and product in membrane bioreactor.Material and Methods: In this work, lactic acid was produced from lactose in membrane bioreactor. A laboratory scale membrane bioreactor was designed and fabricated. Five types of commercial membranes were tested at the same operating conditions (transmembrane pressure: 500 KPa and temperature: 25°C). The effects of initial lactose concentration and dilution rate on biomass growth, lactic acid production and substrate utilization were evaluated.Results and Conclusion: The high lactose retention of 79% v v-1 and low lactic acid retention of 22% v v-1 were obtained with NF1 membrane; therefore, this membrane was selected for membrane bioreactor. The maximal productivity of 17.1 g l-1 h-1 was obtainedwith the lactic acid concentration of 71.5 g l-1 at the dilution rate of 0.24 h−1. The maximum concentration of lactic acid was obtained at the dilution rate of 0.04 h−1. The inhibiting effect of lactic acid was not observed at high initial lactose concentration. The critical lactose concentration at which the cell growth severely hampered was 150 g l-1. This study proved that membrane bioreactor had great advantages such as elimination of substrate and product inhibition, high concentration of process substrate, high cell density,and high lactic acid productivity.Conflict of interest: There is no conflict of interest

Various Techniques for the Surgical Treatment of Common Bile Duct Stones: A Meta Review

Common bile duct stones (CBDSs) may occur in up to 3%–14.7% of all patients for whom cholecystectomy is preformed. Patients presenting with CBDS have symptoms including: biliary colic, jaundice, cholangitis, pancreatitis or may be asymptomatic. It is important to distinguish between primary and secondary stones, because the treatment approach varies. Stones found before, during, and after cholecystectomy had also differing treatments. Different methods have been used for the treatment of CBDS but the suitable therapy depends on conditions such as patient' satisfaction, number and size of stones, and the surgeons experience in laparoscopy. Endoscopic retrograde cholangiopancreatography with or without endoscopic biliary sphincterotomy, laparoscopic CBD exploration (transcystic or transcholedochal), or laparotomy with CBD exploration (by T-tube, C-tube insertion, or primary closure) are the most commonly used methods managing CBDS. We will review the pathophysiology of CBDS, diagnosis, and different techniques of treatment with especial focus on the various surgical modalities

Dynamic Load Altering EV Attacks Against Power Grid Frequency Control

Driven by the necessity to combat climate change, Electric Vehicles (EV) are being deployed to take advantage of their ability in reducing emissions generated by the transportation sector. This deployment has left the power grid vulnerable to attacks through the EV infrastructure. This paper is written from an attacker\'s perspective and proposes a dynamic load altering strategy through manipulating EV charging to destabilize the grid. The attack is formulated based on feedback control theory, i.e., designing an attack based on Linear Matrix Inequalities (LMIs). After the stability metric and controller design have been established, we demonstrate our attack method against the Kundur 2 area grid. The attack scenario includes a cap of 200 MW EV load controlled by the attacker. However, the results show that even with this limitation, the attacker would be successful in pushing the grid toward instability and blackout.Comment: "\c{opyright} 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

Protecting the Future Grid: An Electric Vehicle Robust Mitigation Scheme Against Load Altering Attacks on Power Grids

Due to the growing threat of climate change, the worlds governments have been encouraging the adoption of Electric Vehicles (EVs). As a result, EV numbers have been growing exponentially which will introduce a large EV charging load into the power grid. On this basis, we present a scheme to utilize EVs as a defense mechanism to mitigate Load-Altering (LA) attacks against the grid. The developed scheme relies on robust control theory and Linear Matrix Inequalities (LMIs). Our EV-based defense mechanism is formulated as a feedback controller synthesized using H-2 and H-infinity control techniques to eliminate the impact of unknown LA attacks. The controller synthesis considers the grid topology and the uncertainties of the EV connection to the grid. To demonstrate the effectiveness of the proposed mitigation scheme, it is tested against three types of LA attacks on the New England 39-bus grid. We test our mitigation scheme against 800 MW static, switching, and dynamic attacks in the presence of multiple sources of uncertainty that can affect the EV load during deployment. The results demonstrate how the grid remains stable under the LA attacks that would otherwise lead to serious instabilities.Comment: Accepted for publication in Applied Energ

Prophylactic Oral Calcium Reduces Symptomatic Hypocalcemia in Patients undergoing Total or Subtotal Thyroidectomy: a Randomized Controlled Trial

Objectives: Prophylactic oral calcium supplement has been proposed in patients undergoing thyroidectomy in order to decrease incidence of postoperative hypocalcemia, and the duration of hospital stay. This study aimed to assess the effects of prophylactic oral calcium in patients undergoing total or subtotal thyroidectomy.Methods: Forty three patients who were scheduled for total and subtotal thyroidectomy, were randomly allocated to the case (n=23) and control (n=20) groups. Oral calcium carbonate (1 gram q 8 hours) was given to the patients in the case group starting 12 hours before surgery till 7 days post thyroidectomy. Clinical symptoms of hypocalcemia and postoperative calcium levels were compared between the two groups.Results: The mean postoperative calcium level 12 hours after surgery was not statistically different between the two groups (8.9±0.5 vs. 8.5±0.7, p=0.092); while after 24 hours, calcium level was significantly lower in the control group (8.9±0.5 vs. 8.4±0.8, p=0.037). The number of patients who had paresthesia was significantly higher in the control group than case group, at both 12 hours (p=0.02) and 24 hours postoperatively (p=0.04). Duration of hospitalization was significantly lower in the case group compared to the control group (p=0.006).Conclusions: Prophylactic oral calcium supplementation decreases the hypocalcemia related paresthesia after thyroidectomy and shortens duration of hospital stay

An Electric Vehicle Control Strategy to Mitigate Load Altering Attacks Against Power Grids

Due to growing environmental concerns, the world's governments have been encouraging the shift of the transportation sector towards the adoption of Electric Vehicles (EVs). As a result, EV numbers have been growing exponentially and are expected to continue growing further which will add a large EV charging load to the power grid. To this end, this paper presents an EV-based defense mechanism against Load-Altering (LA) attacks targeting the grid. The developed mechanism utilizes H-infinity controllers and Linear Matrix Inequalities (LMIs) to mitigate LA attacks. After the controller synthesis and presentation of the attack scenarios, we demonstrate the effectiveness and success of our defense mechanism against the three known types of LA attacks. The scenarios include three 800 MW LA attacks against the New England 39-bus grid. The results demonstrate how our EV-based mitigation scheme eliminates the attack impacts and maintains the grid's stability in face of an unknown persisting attack.Comment: Accepted in the 2023 8th IEEE International Conference on Recent Advances and Innovations in Engineering (ICRAIE)-ICRAIE 2023. arXiv admin note: substantial text overlap with arXiv:2308.0752

Outcome of Common Bile Duct Exploration without Intraoperative Cholangiography: a Case Series and Review of Literature

Background: Open or laparoscopic surgical exploration of common bile duct (CBD) is performed when endoscopic approaches fail to extract CBD stones. Intraoperative cholangiography (IOC) through T-tube is performed in order to reduce the rate of retained stones. The aim of this study was to evaluate results of CBD exploration without IOC through T-tube and reviewing existing literature.Methods: A retrospective medical chart review of 392 patients who underwent surgical CBD exploration was performed. All patients had proven CBD stones and had previously undergone failed attempts of endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic sphincterotomy (ES). T-tube insertion or biliary-enteric anastomosis was performed after open CBD exploration with regard to patient’s presentation and CBD diameter. IOC was not performed after T-tube insertion and cholangiography was postponed until 7th postoperative day. Postoperative retained stone and their management were reviewed.Results: Of 392 patients with CBD explorations, T-tube was placed in 215 (54.8%) including 66 (30.7%) emergent biliary drainage and 149 (69.3%) elective operations. A number of 177 of 392 (45.2%) patients underwent biliaryenteric anastomosis. In 6 of 215 patients (2.8%) with T-tube placement, retained CBD stones were detected by T-tube cholangiography during postoperative period. All of them were treated successfully by ERCP.Conclusions: T-tube placement without IOC is accompanied by a low rate of retained stone. Omitting IOC may decrease the operation time which is especially important in emergent cases. Retained stones following CBD exploration and T-tube placement can be treated successfully using ERCP

X-Inactive-Specific Transcript: Review of Its Functions in the Carcinogenesis

X-inactive–specific transcript (XIST) is one of the firstly discovered long non-coding RNAs with prominent roles in the process of X inactivation. Moreover, this transcript contributes in the carcinogenic process in different tissues. In addition to interacting with chromatin modifying molecules, XIST can be served as a molecular sponge for miRNAs to modulate expression of miRNA targets. Most of the studies have indicated an oncogenic role for XIST. However, in prostate cancer, a single study has indicated a tumor suppressor role for this lncRNA. Similar result has been reported for XIST in oral squamous cell carcinoma. In hepatocellular carcinoma, breast cancer, ovarian cancer, osteosarcoma, and renal cell carcinoma, different studies have reported inconsistent results. In the present manuscript, we review function of XIST in the carcinogenesis

Artificial Intelligence in Assessing Cardiovascular Diseases and Risk Factors via Retinal Fundus Images: A Review of the Last Decade

Background: Cardiovascular diseases (CVDs) continue to be the leading cause of mortality on a global scale. In recent years, the application of artificial intelligence (AI) techniques, particularly deep learning (DL), has gained considerable popularity for evaluating the various aspects of CVDs. Moreover, using fundus images and optical coherence tomography angiography (OCTA) to diagnose retinal diseases has been extensively studied. To better understand heart function and anticipate changes based on microvascular characteristics and function, researchers are currently exploring the integration of AI with non-invasive retinal scanning. Leveraging AI-assisted early detection and prediction of cardiovascular diseases on a large scale holds excellent potential to mitigate cardiovascular events and alleviate the economic burden on healthcare systems. Method: A comprehensive search was conducted across various databases, including PubMed, Medline, Google Scholar, Scopus, Web of Sciences, IEEE Xplore, and ACM Digital Library, using specific keywords related to cardiovascular diseases and artificial intelligence. Results: A total of 87 English-language publications, selected for relevance were included in the study, and additional references were considered. This study presents an overview of the current advancements and challenges in employing retinal imaging and artificial intelligence to identify cardiovascular disorders and provides insights for further exploration in this field. Conclusion: Researchers aim to develop precise disease prognosis patterns as the aging population and global CVD burden increase. AI and deep learning are transforming healthcare, offering the potential for single retinal image-based diagnosis of various CVDs, albeit with the need for accelerated adoption in healthcare systems.Comment: 40 pages, 5 figures, 2 tables, 91 reference