Micrometeoroid infall onto Saturn's rings constrains their age to no more than a few hundred million years.

There is ongoing debate as to whether Saturn's main rings are relatively young or ancient- having been formed shortly after Saturn or during the Late Heavy Bombardment. The rings are mostly water-ice but are polluted by non-icy material with a volume fraction ranging from ∼0.1 to 2%. Continuous bombardment by micrometeoroids exogenic to the Saturnian system is a source of this non-icy material. Knowledge of the incoming mass flux of these pollutants allows estimation of the rings' exposure time, providing a limit on their age. Here we report the final measurements by Cassini's Cosmic Dust Analyzer of the micrometeoroid flux into the Saturnian system. Several populations are present, but the flux is dominated by low-relative velocity objects such as from the Kuiper belt. We find a mass flux between 6.9 · 10-17 and 2.7 · 10-16 kg m-2s-1 from which we infer a ring exposure time ≲100 to 400 million years in support of recent ring formation scenarios.

Atraumatic Splenic Rupture in a Patient on Apixaban and Dual Antiplatelet Therapy.

Splenic rupture due to any cause is a life-threatening complication and commonly attributed to trauma. Atraumatic splenic rupture is very rarely reported, and the incidence is currently unknown. Anticoagulants and dual anti-platelet medication can increase the chances of a splenic rupture. Surgical removal of the spleen may be warranted to prevent a life-threatening bleeding. Early identification and intervention are required for most patients as only a few qualify for medical management.

Cytology with rapid on-site examination (ROSE) does not improve diagnostic yield of EUS-FNA of pancreatic cystic lesions.

BACKGROUND: Cytology with rapid on-site evaluation (ROSE) has been shown to increase the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for solid pancreatic lesions. No data exists on the need for rapid onsite cytology in the evaluation of pancreatic cystic lesions (PCLs). The purpose of this study is to determine whether onsite cytology impacts the diagnostic yield of EUS-FNA of PCLs. METHODS: We prospectively examined all patients with PCLs who underwent EUS-FNA without onsite cytology over a 6-month period and compared this to a historical cohort of patients with PCLs who underwent EUS-FNA with ROSE in the previous 6 months. Comparison was made between the two groups based upon patient demographics, EUS cyst characteristics, and FNA fluid & cytopathology results. RESULTS: A total of 100 EUS-FNA exams for PCLs were identified: 46 with ROSE and 54 without onsite cytology. The majority of cytology findings were negative or nondiagnostic, 87.0% in the ROSE group, 77.8% in the group without onsite cytology. There was no difference using EUS-FNA without onsite cytology compared to ROSE when measuring total diagnostic yield (22.2% vs 13.0%, P = .30), number of nondiagnostic specimens (50% vs 54%, P = .69), and number of needle passes (1.51 vs 1.57, P = .68). CONCLUSIONS: (a) The majority of cytology results from EUS-FNA of cystic lesions are negative or nondiagnostic. (b) Having rapid onsite cytology evaluation of cystic lesions does not affect the number of needle passes nor diagnostic yield and is thus not recommended.

Acute Pancreatitis: What's the Score?

BACKGROUND: Acute pancreatitis (AP) is a common presentation in the emergency department (ED). Severity of pancreatitis is an important consideration for ED clinicians making admission judgments. Validated scoring systems can be a helpful tool in this process. OBJECTIVE: The aim of this review is to give a general outline on the subject of AP and compare different criteria used to predict severity of disease for use in the ED. DISCUSSION: This review updates the classifications and scoring systems for AP and the relevant parameters of each. This article assesses past and current scoring systems for AP, including Ranson criteria, Glasgow criteria, Acute Physiology and Chronic Health Evaluation II (APACHE II), computed tomography imaging scoring systems, Bedside Index of Severity in Acute Pancreatitis (BISAP) score, Panc 3, Harmless Acute Pancreatitis Score (HAPS), and the Japanese Severity Score. This article also describes the potential use of single variable predictors. Finally, this article discusses risk factors for early readmission, an outcome pertinent to emergency physicians. These parameters may be used to risk-stratify patients presenting to the ED into mild, moderate, and severe pancreatitis for determination of appropriate disposition. CONCLUSION: Rapid, reliable, and validated means of predicting patient outcome from rapid clinical assessment are of value to the emergency physician. Scoring systems such as BISAP, HAPS, and single-variable predictors may assist in decision-making due to their simplicity of use and applicability within the first 24 h.