Contextual Linear Bandits under Noisy Features: Towards Bayesian Oracles

We study contextual linear bandit problems under uncertainty on features; they are noisy with missing entries. To address the challenges from the noise, we analyze Bayesian oracles given observed noisy features. Our Bayesian analysis finds that the optimal hypothesis can be far from the underlying realizability function, depending on noise characteristics, which is highly non-intuitive and does not occur for classical noiseless setups. This implies that classical approaches cannot guarantee a non-trivial regret bound. We thus propose an algorithm aiming at the Bayesian oracle from observed information under this model, achieving $\tilde{O}(d\sqrt{T})$ regret bound with respect to feature dimension $d$ and time horizon $T$. We demonstrate the proposed algorithm using synthetic and real-world datasets.Comment: 30 page

Case report: Exploring teduglutide as a therapeutic option for refractory microscopic colitis: insights and implications

Microscopic colitis is a chronic inflammatory condition of the colon characterized by chronic watery diarrhea, generally with endoscopically normal or nonspecific findings, and can be diagnosed by histopathological examination of colon mucosal biopsies. Some patients experience severe symptoms that do not respond to conventional medical treatment. A glucagon-like peptide-2 (GLP-2) analog, teduglutide, is used in patients with short bowel syndrome (SBS) dependent on parenteral support. In this case report, we describe a patient with microscopic colitis who demonstrated significant symptom improvement following teduglutide treatment

Association between Estimated Pulse Wave Velocity and Incident Nonalcoholic Fatty Liver Disease in Korean Adults

Introduction: Nonalcoholic fatty liver disease (NAFLD) is associated with vascular dysfunction, one of the signs of which is arterial stiffness. Carotid-femoral pulse wave velocity (PWV), which is considered the gold standard measure of arterial stiffness, can be estimated using two commonly assessed clinical variables: age and blood pressure. This study aimed to evaluate the association between estimated PWV (ePWV) and the prevalence and incidence of NAFLD among Korean adults. Methods: This study used data from the Ansan-Ansung cohort study, a subset of the Korean Genome and Epidemiology Study, and included 8,336 adult participants with and without NAFLD at baseline. The participants were subdivided into three tertile groups according to ePWV. Results: At baseline, the prevalence of NAFLD was 10.5, 27.5, and 35.0% in the first (lowest), second, and third (highest) tertiles of ePWV, respectively. During the 18-year follow-up period, 2,467 (42.9%) incident cases of NAFLD were identified among 5,755 participants who did not have NAFLD at baseline. After adjustment for clinically relevant variables, participants in the second (adjusted hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.12–1.40) and third (adjusted HR, 1.42; 95% CI, 1.24–1.64) tertiles of ePWV had a significantly higher risk of incident NAFLD than those in the first tertile. Conclusion: Higher ePWV is independently associated with an elevated risk of NAFLD in the general population

Novel Natural Polymer/Medicinal Plant Extract Electrospun Nanofiber for Cosmeceutical Application

Zein produced from maize is a hydrophobic protein, which holds great potential for a number of industrial applications, for example, food packaging, pharmaceutical, cosmetic, and biomedical industry. Sorghum, known as important cereal crop worldwide, is a good source of various phytochemicals such as tannins, phenolic acids, anthocyanins, phytosterols, and policosanols, and these phytochemicals have great impact on human health. Poria cocos, a well‐known traditional East‐Asian medicinal plant, is found around the roots of pine trees in Korea and China. As a rapid and efficient process, electrospinning has drawn huge interest among scientists to produce nanostructured polymer materials with excellent properties. In this work, we studied the influence of co‐solvent ratio and concentration of zein/medicinal plant extract on the morphologies of nanostructured zein/medicinal plant extract nanomaterials prepared by electrospinning technique from ethanol/water solution. The zein/medicinal extract nanofibers were characterized by field‐emission scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and differential scanning calorimetric technique. And we were to incorporate medicinal plant resources into the electro‐spun zein nanofibers by electrospinning technique to investigate the effect of medicinal extract on the morphologies, antibacterial, antioxidant, and other properties. Zein/medicinal plant extract might have a practical use as a new preservative for cosmeceutical applications

Molecular insights into DNA interference by CRISPR-associated nuclease-helicase Cas3

Mobile genetic elements in bacteria are neutralized by a system based on clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) proteins. Type I CRISPR-Cas systems use a “Cascade” ribonucleoprotein complex to guide RNA specifically to complementary sequence in invader double-stranded DNA (dsDNA), a process called “interference.” After target recogni- tion by Cascade, formation of an R-loop triggers recruitment of a Cas3 nuclease-helicase, completing the interference process by destroying the invader dsDNA. To elucidate the molecular mecha- nism of CRISPR interference, we analyzed crystal structures of Cas3 from the bacterium Thermobaculum terrenum, with and without a bound ATP analog. The structures reveal a histidine-aspartate (HD)-type nuclease domain fused to superfamily-2 (SF2) helicase domains and a distinct C-terminal domain. Binding of ATP analog at the interface of the SF2 helicase RecA-like domains rearranges a motif V with implications for the enzyme mechanism. The HD- nucleolytic site contains two metal ions that are positioned at the end of a proposed nucleic acid-binding tunnel running through the SF2 helicase structure. This structural alignment suggests a mecha- nism for 3′ to 5′ nucleolytic processing of the displaced strand of invader DNA that is coordinated with ATP-dependent 3′ to 5′ trans- location of Cas3 along DNA. In agreement with biochemical studies, the presented Cas3 structures reveal important mechanistic details on the neutralization of genetic invaders by type I CRISPR-Cas systems

Spinal cord stimulator malfunction caused by radiofrequency neuroablation -A case report-

The implantation of spinal cord stimulators (SCSs) to treat chronic intractable pain is steadily increasing. And there is an increased likelihood of instances where other therapies or procedures are found to interfere with SCS function, which in turn may result in pain. Since SCS utilize electric impulses as well as magnets, special considerations need for patients with a SCS in situ who require these procedures. The present report describes a case where radiofrequency (RF) ablation of the third occipital nerve resulted in spontaneous activation of a cervical SCS device

Assessment of serum biomarkers and coagulation/fibrinolysis markers for prediction of neurological outcomes of out of cardiac arrest patients treated with therapeutic hypothermia

Objective Despite increased survival in patients with cardiac arrest, it remains difficult to determine patient prognosis at the early stage. This study evaluated the prognosis of cardiac arrest patients using brain injury, inflammation, cardiovascular ischemic events, and coagulation/fibrinolysis markers collected 24, 48, and 72 hours after return of spontaneous circulation (ROSC). Methods From January 2011 to December 2016, we retrospectively observed patients who underwent therapeutic hypothermia. Blood samples were collected immediately and 24, 48, and 72 hours after ROSC. Neuron-specific enolase (NSE), S100-B protein, procalcitonin, troponin I, creatine kinase-MB, pro-brain natriuretic protein, D-dimer, fibrin degradation product, antithrombin-III, fibrinogen, and lactate levels were measured. Prognosis was evaluated using Glasgow-Pittsburgh cerebral performance categories and the predictive accuracy of each marker was evaluated. The secondary outcome was whether the presence of multiple markers improved prediction accuracy. Results A total of 102 patients were included in the study: 39 with good neurologic outcomes and 63 with poor neurologic outcomes. The mean NSE level of good outcomes measured 72 hours after ROSC was 18.50 ng/mL. The area under the curve calculated on receiver operating characteristic analysis was 0.92, which showed the best predictive power among all markers included in the study analysis. The relative integrated discrimination improvement and category-free net reclassification improvement models showed no improvement in prognostic value when combined with all other markers and NSE (72 hours). Conclusion Although biomarker combinations did not improve prognostic accuracy, NSE (72 hours) showed the best predictive power for neurological prognosis in patients who received therapeutic hypothermia

Long-term Results of Primary Total Knee Arthroplasty with and without Patellar Resurfacing

Among patients that underwent total knee arthroplasty from June, 1990 to January, 1999, 61 cases (44 patients) that could be followed for more than 10 years were included in this study. The patients were divided into a patellar retention group and a patellar resurfacing group, and were compared with regard to their clinical and radiological outcomes. In patients undergoing primary TKA, a selective patellar resurfacing protocol was used. The indications for patellar retention were a small patella, nearly normal articular cartilage, minimal preoperative patellofemoral pain, poor patellar bone quality, and young patient age. When patellar retention was performed, osteophytes of the patella were removed and marginal electrocauterization was carried out. There were 25 cases (20 patients) in the patellar retention group and 36 cases (29 patients) in the patellar resurfacing group. The mean follow-up period was 140.7 months in the patellar retention group and 149.0 months in the patellar resurfacing group. The selective patellar resurfacing with total knee arthroplasty had a favorable outcome;there were a significant difference noted between the 2 groups in the functional scores, which showed better outcomes in the patellar resurfacing group than in the patellar retention group