Diffusion tensor imaging of frontal lobe white matter tracts in schizophrenia

We acquired diffusion tensor and structural MRI images on 103 patients with schizophrenia and 41 age-matched normal controls. The vector data was used to trace tracts from a region of interest in the anterior limb of the internal capsule to the prefrontal cortex. Patients with schizophrenia had tract paths that were significantly shorter in length from the center of internal capsule to prefrontal white matter. These tracts, the anterior thalamic radiations, are important in frontal-striatal-thalamic pathways. These results are consistent with findings of smaller size of the anterior limb of the internal capsule in patients with schizophrenia, diffusion tensor anisotropy decreases in frontal white matter in schizophrenia and hypothesized disruption of the frontal-striatal-thalamic pathway system

A systematic review of the relationship between subchondral bone features, pain and structural pathology in peripheral joint osteoarthritis

Introduction: Bone is an integral part of the osteoarthritis (OA) process. We conducted a systematic literature review in order to understand the relationship between non-conventional radiographic imaging of subchondral bone, pain, structural pathology and joint replacement in peripheral joint OA. Methods: A search of the Medline, EMBASE and Cochrane library databases was performed for original articles reporting association between non-conventional radiographic imaging-assessed subchondral bone pathologies and joint replacement, pain or structural progression in knee, hip, hand, ankle and foot OA. Each association was qualitatively characterised by a synthesis of the data from each analysis based upon study design, adequacy of covariate adjustment and quality scoring. Results: In total 2456 abstracts were screened and 139 papers were included (70 cross-sectional, 71 longitudinal analyses; 116 knee, 15 hip, six hand, two ankle and involved 113 MRI, eight DXA, four CT, eight scintigraphic and eight 2D shape analyses). BMLs, osteophytes and bone shape were independently associated with structural progression or joint replacement. BMLs and bone shape were independently associated with longitudinal change in pain and incident frequent knee pain respectively. Conclusion: Subchondral bone features have independent associations with structural progression, pain and joint replacement in peripheral OA in the hip and hand but especially in the knee. For peripheral OA sites other than the knee, there are fewer associations and independent associations of bone pathologies with these important OA outcomes which may reflect fewer studies; for example the foot and ankle were poorly studied. Subchondral OA bone appears to be a relevant therapeutic target. Systematic review: PROSPERO registration number: CRD 4201300500

Annals of Solid and Structural Mechanics

In this paper, the effects of a breathing crack on the vibratory characteris- tics of a rotating shaft are investigated. A new, simple and robust model composed of two rigid bars connected with a nonlinear flexural spring is proposed. The nonlinear spring, located at the cracked transverse section position, concentrates the global stiff- ness of the cracked shaft. The breathing mechanism of the crack is described by a more realistic periodic variation of the global stiffness depending not only but substantially on the system vibratory response. It is based on an energy formulation of the problem of 3D elasticity with unilateral contact conditions on the crack lips. A possible partial opening and closing of the crack is considered which makes the approach more appro- priate for deep cracks modeling. The harmonic balance method, direct time-integration schemes and nonlinear dynamics tools are used to characterize the global dynamics of the system. The effects of the crack depth and rotating frequency have been metic- ulously examined and it was found that the cracked shaft never exhibits chaotic or quasi-periodic vibratory response

Parametric estimation for the standard and geometric telegraph process observed at discrete times

Telegraph process, Discretely observed process, Inference for stochastic processes, Primary 60K99, Secondary 62M99,

Diagnosis and management of acute variceal bleeding: Asian Pacific Association for Study of the Liver recommendations

Acute variceal bleeding (AVB) is a medical emergency and associated with a mortality of 20% at 6 weeks. Significant advances have occurred in the recent past and hence there is a need to update the existing consensus guidelines. There is also a need to include the literature from the Eastern and Asian countries where majority of patients with portal hypertension (PHT) live. The expert working party, predominantly from the Asia-Pacific region, reviewed the existing literature and deliberated to develop consensus guidelines. The working party adopted the Oxford system for developing an evidence-based approach. Only those statements that were unanimously approved by the experts were accepted. AVB is defined as a bleed in a known or suspected case of PHT, with the presence of hematemesis within 24 h of presentation, and/or ongoing melena, with last melanic stool within last 24 h. The time frame for the AVB episode is 48 h. AVB is further classified as active or inactive at the time of endoscopy. Combination therapy with vasoactive drugs (< 30 min of hospitalization) and endoscopic variceal ligation (door to scope time < 6 h) is accepted as first-line therapy. Rebleeding (48 h of T (0)) is further sub-classified as very early rebleeding (48 to 120 h from T (0)), early rebleeding (6 to 42 days from T (0)) and late rebleeding (after 42 days from T (0)) to maintain uniformity in clinical trials. Emphasis should be to evaluate the role of adjusted blood requirement index (ABRI), assessment of associated comorbid conditions and poor predictors of non-response to combination therapy, and proposed APASL (Asian Pacific Association for Study of the Liver) Severity Score in assessing these patients. Role of hepatic venous pressure gradient in AVB is considered useful. Antibiotic (cephalosporins) prophylaxis is recommended and search for acute ischemic hepatic injury should be done. New guidelines have been developed for management of variceal bleed in patients with non-cirrhotic PHT and variceal bleed in pediatric patients. Management of acute variceal bleeding in Asia-Pacific region needs special attention for uniformity of treatment and future clinical trials