Predictors of Survival Among the Oldest Old Following Acute Hospital Admission: Insights From Clinical and Biochemical Factors.

Understanding the factors influencing survival in oldest old population is crucial for providing appropriate care and improving outcomes. This prospective observational study aimed to investigate the determinants of survival in acutely ill oldest old patients during acute hospitalization and 1-month follow-up. Various geriatric domains and biochemical markers were assessed. Among the 70 included patients with a median age of 87 (Inter quartile range: 85-90), the presence of diabetes, delirium, tachypnea, and high sirtuin-5 levels were associated with reduced in-hospital survival. Non-survivors had raised levels of Sirtuin 1 and Sirtuin 5, with an increase of 43% and 70%, respectively. At 1 month, delirium and diabetes were still associated with reduced survival. These findings suggest that type-2 diabetes, delirium, tachypnea, and high sirtuin-5 levels could serve as predictors of reduced survival in acutely ill, hospitalized oldest old patients.

Recurrent syncope in long survivors and its association with geriatric syndromes.

Objective: Syncope is a common clinical condition in the elderly, associated with significant morbidity and risk of recurrence. Recurrent syncope causing a repeated reduction in the cerebral blood flow can predispose to progressive neurodegeneration, a decline in overall health and functionality. Hence, this study was conducted to study the common causes of recurrent syncope and its association with various geriatric syndromes. Methodology: This case-control study recruited 50 cases of recurrent syncope and 50 controls, aged 75 years and older. A detailed history and sequential evaluation for aetiologies of recurrent syncope were done. Cognition, frailty, activities of daily living, depression, and nutrition were assessed using various scales. Results: Most (80%, 80/100) of the participants were males and the mean age was 80.04 ± 4.3 years. In the syncope group, 42% (21/50) of patients had arrhythmia, and 30% (15/30) had valvular heart disease. Recurrent syncope was significantly associated with lower scores on Montreal cognitive assessment scale (OR: 6.47 P < 0.001), four or more comorbidities (OR: 6.29 P < 0.001), and hearing impairment (OR: 6.21 P < 0.004) on multivariate logistic regression analysis. Conclusion: Recurrent syncope is significantly associated with cognitive impairment, the presence of four or more comorbidities, and hearing impairment. Conduction abnormality was the most common etiology of recurrent cardiovascular syncope. Structured evaluation and appropriate management of recurrent syncope might reduce the decline in physical, cognitive, and psychological reserve. A follow-up longitudinal study is needed to establish this.

Prominent Neck and Pinna Pulsations.

A young man presented with visible neck and pinna pulsations after a palliative bidirectional cavopulmonary (Glenn) shunt with open antegrade flow. This resulted in giant C-V waves in the jugular venous pulse. Giant C-V waves resulting from a Glenn procedure have not previously been described and represent a novel entity to recognize. (Level of Difficulty: Advanced.).

Manipulation of gold colloidal nanoparticles with atomic force microscopy in dynamic mode: influence of particle-substrate chemistry and morphology, and of operating conditions.

One key component in the assembly of nanoparticles is their precise positioning to enable the creation of new complex nano-objects. Controlling the nanoscale interactions is crucial for the prediction and understanding of the behaviour of nanoparticles (NPs) during their assembly. In the present work, we have manipulated bare and functionalized gold nanoparticles on flat and patterned silicon and silicon coated substrates with dynamic atomic force microscopy (AFM). Under ambient conditions, the particles adhere to silicon until a critical drive amplitude is reached by oscillations of the probing tip. Beyond that threshold, the particles start to follow different directions, depending on their geometry, size and adhesion to the substrate. Higher and respectively, lower mobility was observed when the gold particles were coated with methyl (-CH(3)) and hydroxyl (-OH) terminated thiol groups. This major result suggests that the adhesion of the particles to the substrate is strongly reduced by the presence of hydrophobic interfaces. The influence of critical parameters on the manipulation was investigated and discussed viz. the shape, size and grafting of the NPs, as well as the surface chemistry and the patterning of the substrate, and finally the operating conditions (temperature, humidity and scan velocity). Whereas the operating conditions and substrate structure are shown to have a strong effect on the mobility of the particles, we did not find any differences when manipulating ordered vs random distributed particles.

Controlling adhesion force by means of nanoscale surface roughness.

Control of adhesion is a crucial aspect in the design of microelectromechanical and nanoelectromechanical devices. To understand the dependence of adhesion on nanometer-scale surface roughness, a roughness gradient has been employed. Monomodal roughness gradients were fabricated by means of silica nanoparticles (diameter ∼12 nm) to produce substrates with varying nanoparticle density. Pull-off force measurements on the gradients were performed using (polyethylene) colloidal-probe microscopy under perfluorodecalin, in order to restrict interactions to van der Waals forces. The influence of normal load on pull-off forces was studied and the measured forces compared with existing Hamaker-approximation-based models. We observe that adhesion force reaches a minimum value at an optimum particle density on the gradient sample, where the mean particle spacing becomes comparable with the diameter of the contact area with the polyethylene sphere. We also observe that the effect on adhesion of increasing the normal load depends on the roughness of the surface.

Controlled manipulation of rigid nanorods by atomic force microscopy.

The motion of rigid nanorods caused by the normal vibrations of a nanotip rastering a flat surface is described within an original collisional model. Provided that the friction between the nanorods and the surface is sufficiently high, the direction of motion and the orientation of the nanorods are determined by two pairs of differential equations. In the limiting case of thin nanowires, the direction of motion is precisely related to the length of the nanowire, the tip radius and the density of the scan lines. At the same time the wire oscillates perpendicularly to this direction in a characteristic wobbling motion. Similar conclusions approximately hold also when the rod thickness is not negligible (compared to its length), as shown by a comparison between numerical solutions of our model and measurements on gold nanorods manipulated on a silicon oxide surface. Our results open the path to understanding and controlling the manipulation of arbitrarily shaped nanoparticles.