Adversarial Matching of Dark Net Market Vendor Accounts

Many datasets feature seemingly disparate entries that actually refer to the same entity. Reconciling these entries, or matching, is challenging, especially in situations where there are errors in the data. In certain contexts, the situation is even more complicated: an active adversary may have a vested interest in having the matching process fail. By leveraging eight years of data, we investigate one such adversarial context: matching different online anonymous marketplace vendor handles to unique sellers. Using a combination of random forest classifiers and hierarchical clustering on a set of features that would be hard for an adversary to forge or mimic, we manage to obtain reasonable performance (over 75% precision and recall on labels generated using heuristics), despite generally lacking any ground truth for training. Our algorithm performs particularly well for the top 30% of accounts by sales volume, and hints that 22,163 accounts with at least one confirmed sale map to 15,652 distinct sellers---of which 12,155 operate only one account, and the remainder between 2 and 11 different accounts. Case study analysis further confirms that our algorithm manages to identify non-trivial matches, as well as impersonation attempts

First-trimester cesarean scar pregnancy: a comparative analysis of treatment options from the international registry

Background: A cesarean scar pregnancy is an iatrogenic consequence of a previous cesarean delivery. The gestational sac implants into a niche created by the incision of the previous cesarean delivery, and this carries a substantial risk for major maternal complications. The aim of this study was to report, analyze, and compare the effectiveness and safety of different treatments options for cesarean scar pregnancies managed in the first trimester through a registry. Objective: This study aimed to evaluated the ultrasound findings, disease behavior, and management of first-trimester cesarean scar pregnancies. Study design: We created an international registry of cesarean scar pregnancy cases to study the ultrasound findings, disease behavior, and management of cesarean scar pregnancies. The Cesarean Scar Pregnancy Registry collects anonymized ultrasound and clinical data of individual patients with a cesarean scar pregnancy on a secure, digital information platform. Cases were uploaded by 31 participating centers across 19 countries. In this study, we only included live and failing cesarean scar pregnancies (with or without a positive fetal heart beat) that received active treatment (medical or surgical) before 12+6 weeks' gestation to evaluate the effectiveness and safety of the different management options. Patients managed expectantly were not included in this study and will be reported separately. Treatment was classified as successful if it led to a complete resolution of the pregnancy without the need for any additional medical interventions. Results: Between August 29, 2018, and February 28, 2023, we recorded 460 patients with cesarean scar pregnancies (281 live, 179 failing cesarean scar pregnancy) who fulfilled the inclusion criteria and were registered. A total of 270 of 460 (58.7%) patients were managed surgically, 123 of 460 (26.7%) patients underwent medical management, 46 of 460 (10%) patients underwent balloon management, and 21 of 460 (4.6%) patients received other, less frequently used treatment options. Suction evacuation was very effective with a success rate of 202 of 221 (91.5%; 95% confidence interval, 87.8-95.2), whereas systemic methotrexate was least effective with only 38 of 64 (59.4%; 95% confidence interval, 48.4-70.4) patients not requiring additional treatment. Overall, surgical treatment of cesarean scar pregnancies was successful in 236 of 258 (91.5%, 95% confidence interval, 88.4-94.5) patients and complications were observed in 24 of 258 patients (9.3%; 95% confidence interval, 6.6-11.9). Conclusion: A cesarean scar pregnancy can be managed effectively in the first trimester of pregnancy in more than 90% of cases with either suction evacuation, balloon treatment, or surgical excision. The effectiveness of all treatment options decreases with advancing gestational age, and cesarean scar pregnancies should be treated as early as possible after confirmation of the diagnosis. Local medical treatment with potassium chloride or methotrexate is less efficient and has higher rates of complications than the other treatment options. Systemic methotrexate has a substantial risk of failing and a higher complication rate and should not be recommended as first-line treatment

Are CT-Based Finite Element Model Predictions of Femoral Bone Strengthening Clinically Useful?

Purpose of Review: This study reviews the available literature to compare the accuracy of areal bone mineral density derived from dual X-ray absorptiometry (DXA-aBMD) and of subject-specific finite element models derived from quantitative computed tomography (QCT-SSFE) in predicting bone strength measured experimentally on cadaver bones, as well as their clinical accuracy both in terms of discrimination and prediction. Based on this information, some basic cost-effectiveness calculations are performed to explore the use of QCT-SSFE instead of DXA-aBMD in (a) clinical studies with femoral strength as endpoint, (b) predictor of the risk of hip fracture in low bone mass patients. Recent Findings: Recent improvements involving the use of smooth-boundary meshes, better anatomical referencing for proximal-only scans, multiple side-fall directions, and refined boundary conditions increase the predictive accuracy of QCT-SSFE. Summary: If these improvements are adopted, QCT-SSFE is always preferable over DXA-aBMD in clinical studies with femoral strength as the endpoint, while it is not yet cost-effective as a hip fracture risk predictor, although pathways that combine both QCT-SSFE and DXA-aBMD are promising

In vitro and in vivo evaluation of 3D constructs engineered with human iPSC-derived chondrocytes in gelatin methacryloyl hydrogel

Articular cartilage defects have limited healing potential and, when left untreated, can lead to osteoarthritis. Tissue engineering focuses on regenerating the damaged joint surface, preferably in an early stage. Here, we investigate the regenerative potential of three-dimensional (3D) constructs consisting of human induced pluripotent stem cell (iPSC)-derived chondrocytes in gelatin methacryloyl (GelMA) hydrogel for stable hyaline cartilage production. iPSC-derived chondrocytes are encapsulated in GelMA hydrogel at low (1 x 10(7) ml(-1)) and high (2 x 10(7) ml(-1)) density. In a conventional medium, GelMA hydrogel supports the chondrocyte phenotype, as opposed to cells cultured in 3D in absence of hydrogel. Moreover, encapsulated iPSC-derived chondrocytes preserve their in vivo matrix formation capacity after 21 days in vitro. In differentiation medium, hyaline cartilage-like tissue forms after 21 days, demonstrated by highly sulfated glycosaminoglycans and collagen type II. Matrix deposition is delayed at low encapsulation density, corroborating with lower transcript levels of COL2A1. An ectopic assay in nude mice demonstrates further maturation of the matrix deposited in vitro. Direct ectopic implantation of iPSC-derived chondrocyte-laden GelMA, without in vitro priming, also generates hyaline cartilage-like tissue, albeit less mature. Since it is unclear what maturity upon implantation is desired for joint surface regeneration, this is an attractive technology to generate immature and more mature hyaline cartilage-like tissue

Skeletal Muscles of Patients Infected with SARS-CoV-2 Develop Severe Myofiber Damage upon One Week of Admission on the Intensive Care Unit

Many critically ill patients infected with SARS-CoV-2 have been submitted to an intensive care unit (ICU). Patients with a SARS-CoV-2 infection that survive critical illness are confronted with months of physical impairments. To maximize recovery, it is important to understand the musculoskeletal involvement in critically ill patients infected with SARS-CoV-2. The aim of the present study was to assess the myocellular changes in SARS-CoV-2 patients that occur throughout the first week of ICU admission. In n = 22 critically ill patients infected with SARS-CoV-2, a biopsy sample from the vastus lateralis muscle was obtained at day 1–3 and day 5–8 following ICU admission. Fluorescence microscopy was used to assess type I and type II muscle fiber size and distribution, myonuclear content, and muscle tissue capillarization. Transmission electron microscopy was used to support quantitative data at an ultrastructural level. Changes in type I and type II muscle fiber size showed large inter-individual variation. The average change in type I fiber size was +309 ± 1834 µm2, ranging from −2129 µm2 (−31%) to +3375 µm2 (+73%). The average change in type II fiber size was −224 ± 1256 µm2, ranging from −1410 µm2 (−36%) to +2592 µm2 (+48%). Ultrastructural observations showed myofibrillar and hydropic degeneration, and fiber necrosis. This study shows that ICU patients admitted with SARS-CoV-2 suffer from substantial muscle fiber damage during ICU admission. These results are a call for action towards more specialized rehabilitation programs for patients admitted to the ICU with SARS-CoV-2 infection