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Cellulose nanocrystals (CNC) are naturally-derived nanostructures of growing importance for the production of composites having attractive mechanical properties, and offer improved sustainability over purely petroleum-based alternatives. Fabrication of CNC composites typically involves extrusion of CNC suspensions and gels in a variety of solvents, in the presence of additives such as polymers and curing agents. Most studies so far have focused on aqueous CNC gels, yet the behavior of CNC-polymer gels in organic solvents is important to their wider processability. Here, we study the rheological behavior of composite polymer-CNC gels in dimethylformamide, which include additives for both UV and thermal crosslinking. Using rheometry coupled with in situ infrared spectroscopy, we show that under external shear, CNC-polymer gels display progressive and irreversible failure of the hydrogen bond network that is responsible for their pronounced elastic properties. In the absence of cross-linking additives, the polymer-CNC gels show an instantaneous but partial recovery of their viscoelasticity upon cessation of flow, whereas, the presence of additives allows the gels to recover over much longer timescale via van der Waals interactions. By exploring a broad range of shear history and CNC concentrations, we construct master curves for the temporal evolution of the viscoelastic properties of the polymer-CNC gels, illustrating universality of the observed dynamics with respect to gel composition and flow conditions. We find that polymer-CNC composite gels display a number of the distinctive features of colloidal glasses and, strikingly, that their response to the flow conditions encountered during processing can be tuned by chemical additives. These findings have implications for processing of dense CNC-polymer composites in solvent casting, 3D printing, and other manufacturing techniques.
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The implantation of an implantable cardioverter defibrillator (ICD) carries a risk for major complications, one of which is ventricular free wall rupture secondary to a lead perforation. This known complication, although rare, has estimated incidence rates between 0.1% and 3%. Predictive factors of such an event include temporary leads, steroid use, active fixation leads, low body mass index (<20 kg/m2), age greater than 80 years, female gender, and concurrent anticoagulation. Right ventricular systolic pressure >35 mmHg is considered a protective factor likely due to associated right ventricular hypertrophy. We present a case of a 73-year-old female with a history of aortic stenosis status post-transcatheter aortic valve replacement (TAVR) and atrial fibrillation (AFib) who met the criteria for an ICD after suffering ventricular fibrillation arrest (after TAVR procedure) ultimately resulting in lead perforation.
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Lymphoplasmacytic lymphoma (LPL) is an uncommon condition, accounting for only 2% of all non-Hodgkin's lymphoma cases. Individuals with LPL face the risk of vascular blockage when associated with type I cryoglobulinemia, leading to related symptoms. Until now, no instances of LPL with dry gangrene have been documented. However, we present a rare case involving LPL accompanied by dry gangrene in both the right upper extremity (RUE) and left lower extremity (LLE). The patient was effectively managed using a combination of chemotherapy, steroids, plasmapheresis, and salvage surgery.
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Laughing gas is becoming increasingly popular as a recreational drug of choice, particularly among young adults. Nitrous oxide, the toxic component of laughing gas, can cause neuronal injury when used in high doses. Through multiple mechanisms, nitrous oxide leads to B12 depletion and subsequent demyelination, particularly in the spinal cord. Here, we present the case of a 27-year-old female who presented with ataxia and was found to have laughing gas-induced subacute combined degeneration from nitrous oxide. After aggressive vitamin B12 repletion and laughing gas cessation for three months, the patient improved.
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Introduction Hyperlipidemia is prevalent worldwide and affects a significant number of US adults. It significantly contributes to ischemic heart disease and millions of deaths annually. With the increasing use of the internet for health information, tools like ChatGPT (OpenAI, San Francisco, CA, USA) have gained traction. ChatGPT version 4.0, launched in March 2023, offers enhanced features over its predecessor but requires a monthly fee. This study compares the accuracy, comprehensibility, and response length of the free and paid versions of ChatGPT for patient education on hyperlipidemia. Materials and methods ChatGPT versions 3.5 and 4.0 were prompted in three different ways and 25 questions from the Cleveland Clinic's frequently asked questions (FAQs) on hyperlipidemia. Prompts included no prompting (Form 1), patient-friendly prompting (Form 2), and physician-level prompting (Form 3). Responses were categorized as incorrect, partially correct, or correct. Additionally, the grade level and word count from each response were recorded for analysis. Results Overall, scoring frequencies for ChatGPT version 3.5 were: five (6.67%) incorrect, 18 partially correct (24%), and 52 (69.33%) correct. Scoring frequencies for ChatGPT version 4.0 were: one (1.33%) incorrect, 18 (24.00%) partially correct, and 56 (74.67%) correct. Correct answers did not significantly differ between ChatGPT version 3.5 and ChatGPT version 4.0 (p = 0.586). ChatGPT version 3.5 had a significantly higher grade reading level than version 4.0 (p = 0.0002). ChatGPT version 3.5 had a significantly higher word count than version 4.0 (p = 0.0073). Discussion There was no significant difference in accuracy between the free and paid versions of hyperlipidemia FAQs. Both versions provided accurate but sometimes partially complete responses. Version 4.0 offered more concise and readable information, aligning with the readability of most online medical resources despite exceeding the National Institutes of Health's (NIH's) recommended eighth-grade reading level. The paid version demonstrated superior adaptability in tailoring responses based on the input. Conclusion Both versions of ChatGPT provide reliable medical information, with the paid version offering more adaptable and readable responses. Healthcare providers can recommend ChatGPT as a source of patient education, regardless of the version used. Future research should explore diverse question formulations and ChatGPT's handling of incorrect information.
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Gallstones, or cholelithiasis, represent a prevalent gastrointestinal disorder characterized by the formation of calculi within the gallbladder. This review aims to provide a comprehensive analysis of the complications associated with gallstones, with a focus on their pathophysiology, clinical manifestations, diagnostic methodologies, and management strategies. Gallstone-related complications encompass a broad spectrum, including biliary colic, acute cholecystitis, choledocholithiasis, acute pancreatitis, and cholangitis. The pathogenesis of these complications primarily involves biliary obstruction and subsequent infection, leading to significant morbidity and potential mortality. Diagnostic evaluation of gallstone complications employs various imaging techniques, such as ultrasonography, magnetic resonance cholangiopancreatography (MRCP), and endoscopic retrograde cholangiopancreatography (ERCP), each with distinct advantages and limitations. Therapeutic approaches are discussed, ranging from conservative management with pharmacotherapy and bile acid dissolution agents to interventional procedures like extracorporeal shock wave lithotripsy (ESWL) and percutaneous cholecystostomy. Surgical management, particularly laparoscopic cholecystectomy, remains the gold standard for definitive treatment. Additionally, advancements in endoscopic techniques, including endoscopic sphincterotomy (EST) and cholangioscopy, are highlighted. This review synthesizes current research findings and clinical guidelines, aiming to enhance the understanding and management of gallstone-related complications among healthcare professionals, thereby improving patient outcomes and reducing the burden of this common ailment.
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Background ChatGPT is a language model that has gained widespread popularity for its fine-tuned conversational abilities. However, a known drawback to the artificial intelligence (AI) chatbot is its tendency to confidently present users with inaccurate information. We evaluated the quality of ChatGPT responses to questions pertaining to atrial fibrillation for patient education. Our analysis included the accuracy and estimated grade level of answers and whether references were provided for the answers. Methodology ChatGPT was prompted four times and 16 frequently asked questions on atrial fibrillation from the American Heart Association were asked. Prompts included Form 1 (no prompt), Form 2 (patient-friendly prompt), Form 3 (physician-level prompt), and Form 4 (prompting for statistics/references). Responses were scored as incorrect, partially correct, or correct with references (perfect). Flesch-Kincaid grade-level unique words and response lengths were recorded for answers. Proportions of the responses at differing scores were compared using the chi-square analysis. The relationship between form and grade level was assessed using the analysis of variance. Results Across all forms, scoring frequencies were one (1.6%) incorrect, five (7.8%) partially correct, 55 (85.9%) correct, and three (4.7%) perfect. Proportions of responses that were at least correct did not differ by form (p = 0.350), but perfect responses did (p = 0.001). Form 2 answers had a lower mean grade level (12.80 ± 3.38) than Forms 1 (14.23 ± 2.34), 3 (16.73 ± 2.65), and 4 (14.85 ± 2.76) (p < 0.05). Across all forms, references were provided in only three (4.7%) answers. Notably, when additionally prompted for sources or references, ChatGPT still only provided sources on three responses out of 16 (18.8%). Conclusions ChatGPT holds significant potential for enhancing patient education through accurate, adaptive responses. Its ability to alter response complexity based on user input, combined with high accuracy rates, supports its use as an informational resource in healthcare settings. Future advancements and continuous monitoring of AI capabilities will be crucial in maximizing the benefits while mitigating the risks associated with AI-driven patient education.
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A 73-year-old male with hyperlipidemia and prior squamous cell carcinoma presented with a new-onset generalized tonic-clonic seizure and left-sided weakness. He had a progressively worsening cervical and occipital headache for nine days and was initially evaluated with an unremarkable CT head. The patient arrived at the emergency department with a left gaze deviation, prompting a "Code Neuro." CT angiography (CTA) detected a large dural sinus thrombosis, which was confirmed with a CT venogram and brain MRI. The patient was closely monitored in the intensive care unit and managed with heparin, nicardipine, and hypertonic saline boluses. Neurosurgery opted against surgical intervention. EEG revealed right hemisphere focal dysfunction. Recanalization occurred on hospital day 6. The patient was transitioned to apixaban upon discharge and instructed to follow up with hematology for a hypercoagulable workup. This case highlights the diagnostic complexity of cerebral venous sinus thrombosis (CVST), urging consideration of a differential even in atypical patients. We hope reporting this case will prompt clinicians to consider CVST in patients with non-specific symptoms, leading to timely diagnosis and treatment.
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Gastrointestinal stromal tumors (GISTs) are rare in young individuals and typically affect older adults. We present the case of a previously healthy male who presented with severe hematochezia, fatigue, and dizziness. Colonoscopy did not demonstrate any colonic mass. CT of the pelvis with contrast revealed a pelvic mass measuring 7.4 cm. Biopsy confirmed a low-grade mixed-type GIST of the terminal ileum. Surgical resection was successfully performed. Histopathological analysis further characterized the tumor, and the patient was discharged with consideration of adjuvant imatinib therapy. This case underscores the importance of thorough diagnostic evaluation and multidisciplinary management for atypical presentations of gastrointestinal bleeding in young patients.
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Nonalcoholic Fatty Liver Disease (NAFLD) is a growing global phenomenon, and its damaging effects in terms of cardiovascular disease (CVD) risk are becoming more apparent. NAFLD is estimated to affect around one quarter of the world population and is often comorbid with other metabolic disorders including diabetes mellitus, hypertension, coronary artery disease, and metabolic syndrome. In this review, we examine the current evidence describing the many ways that NAFLD itself increases CVD risk. We also discuss the emerging and complex biochemical relationship between NAFLD and its common comorbid conditions, and how they coalesce to increase CVD risk. With NAFLD's rising prevalence and deleterious effects on the cardiovascular system, a complete understanding of the disease must be undertaken, as well as effective strategies to prevent and treat its common comorbid conditions.
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Neural circuits underlying brain functions are vulnerable to damage, including ischemic injury, leading to neuronal loss and gliosis. Recent technology of direct conversion of endogenous astrocytes into neurons in situ can simultaneously replenish the neuronal population and reverse the glial scar. However, whether these newly reprogrammed neurons undergo normal development, integrate into the existing neuronal circuit, and acquire functional properties specific for this circuit is not known. We investigated the effect of NeuroD1-mediated in vivo direct reprogramming on visual cortical circuit integration and functional recovery in a mouse model of ischemic injury. After performing electrophysiological extracellular recordings and two-photon calcium imaging of reprogrammed cells in vivo and mapping the synaptic connections formed onto these cells ex vivo, we discovered that NeuroD1 reprogrammed neurons were integrated into the cortical microcircuit and acquired direct visual responses. Furthermore, following visual experience, the reprogrammed neurons demonstrated maturation of orientation selectivity and functional connectivity. Our results show that NeuroD1-reprogrammed neurons can successfully develop and integrate into the visual cortical circuit leading to vision recovery after ischemic injury.