Review of human supraspinatus tendon mechanics. Part I: fatigue damage accumulation and failure.

Repetitive stress injuries to the rotator cuff, and particularly the supraspinatus tendon (SST), are highly prevalent and debilitating. These injuries typically occur through the application of cyclic load below the threshold necessary to cause acute tears, leading to accumulation of incremental damage that exceeds the body's ability to heal, resulting in decreased mechanical strength and increased risk of frank rupture at lower loads. Consistent progression of fatigue damage across multiple model systems suggests a generalized tendon response to overuse.

Review of human supraspinatus tendon mechanics. Part II: tendon healing response and characterization of tendon health.

Overuse injuries of the rotator cuff, particularly of the supraspinatus tendon (SST), are highly prevalent and debilitating in work, sport, and daily activities. Despite the clinical significance of these injuries, there remains a large degree of uncertainty regarding the pathophysiology of injury, optimal methods of nonoperative and operative repair, and how to adequately assess tendon injury and healing. The tendon response to fatigue damage resulting from overuse is different from that of acute rupture and results in either an adaptive (healing) or a maladaptive (degenerative) response.

Grid-cell modules remain coordinated when neural activity is dissociated from external sensory cues.

The representation of an animal's position in the medial entorhinal cortex (MEC) is distributed across several modules of grid cells, each characterized by a distinct spatial scale. The population activity within each module is tightly coordinated and preserved across environments and behavioral states. Little is known, however, about the coordination of activity patterns across modules.

Toroidal topology of population activity in grid cells.

The medial entorhinal cortex is part of a neural system for mapping the position of an individual within a physical environment. Grid cells, a key component of this system, fire in a characteristic hexagonal pattern of locations, and are organized in modules that collectively form a population code for the animal's allocentric position. The invariance of the correlation structure of this population code across environments and behavioural states, independent of specific sensory inputs, has pointed to intrinsic, recurrently connected continuous attractor networks (CANs) as a possible substrate of the grid pattern.

Task-dependent mixed selectivity in the subiculum.

CA1 and subiculum (SUB) connect the hippocampus to numerous output regions. Cells in both areas have place-specific firing fields, although they are more dispersed in SUB. Weak responses to head direction and running speed have been reported in both regions.

Neuropixels 2.0: A miniaturized high-density probe for stable, long-term brain recordings.

Measuring the dynamics of neural processing across time scales requires following the spiking of thousands of individual neurons over milliseconds and months. To address this need, we introduce the Neuropixels 2.0 probe together with newly designed analysis algorithms.

Correlation structure of grid cells is preserved during sleep.

The network of grid cells in the medial entorhinal cortex (MEC) forms a fixed reference frame for mapping physical space. The mechanistic origin of the grid representation is unknown, but continuous attractor network models explain multiple fundamental features of grid cell activity. An untested prediction of these models is that the grid cell network should exhibit an activity correlation structure that transcends behavioral states.

Efficacy of Articaine versus Lidocaine in Supplemental Infiltration for Mandibular First versus Second Molars with Irreversible Pulpitis: A Prospective, Randomized, Double-blind Clinical Trial.

Introduction: Profound pulpal anesthesia is difficult to achieve in mandibular molars with irreversible pulpitis (IP). However, there are no published randomized controlled clinical trials comparing the success of supplemental buccal infiltration (BI) in mandibular first versus second molars with IP. The purpose of this prospective, randomized, double-blind study was to compare the efficacy of 4% articaine with 2% lidocaine for supplemental BIs in mandibular first versus second molars with IP after a failed inferior alveolar nerve block (IANB).

Efficacy of articaine versus lidocaine as a supplemental buccal infiltration in mandibular molars with irreversible pulpitis: a prospective, randomized, double-blind study.

Introduction: Profound pulpal anesthesia in mandibular molars with irreversible pulpitis (IP) is often difficult to obtain and often requires supplemental injections after an ineffective inferior alveolar nerve block (IANB). The purpose of this prospective, randomized, double-blind study was to compare the efficacy of 4% articaine with 2% lidocaine for supplemental buccal infiltrations (BIs) after an ineffective IANB in mandibular molars with IP. In addition, the use of articaine for IANB and intraosseous injections was investigated.

Neural oscillations during non-rapid eye movement sleep as biomarkers of circuit dysfunction in schizophrenia.

The neurophysiology of non-rapid eye movement sleep is characterized by the occurrence of neural network oscillations with distinct origins and frequencies, which act in concert to support sleep-dependent information processing. Thalamocortical circuits generate slow (0.25-4 Hz) oscillations reflecting synchronized temporal windows of cortical activity, whereas concurrent waxing and waning spindle oscillations (8-15 Hz) act to facilitate cortical plasticity.

Differential spike timing and phase dynamics of reticular thalamic and prefrontal cortical neuronal populations during sleep spindles.

The 8-15 Hz thalamocortical oscillations known as sleep spindles are a universal feature of mammalian non-REM sleep, during which they are presumed to shape activity-dependent plasticity in neocortical networks. The cortex is hypothesized to contribute to initiation and termination of spindles, but the mechanisms by which it implements these roles are unknown. We used dual-site local field potential and multiple single-unit recordings in the thalamic reticular nucleus (TRN) and medial prefrontal cortex (mPFC) of freely behaving rats at rest to investigate thalamocortical network dynamics during natural sleep spindles.

Geometric reconstruction methods for electron tomography.

Electron tomography is becoming an increasingly important tool in materials science for studying the three-dimensional morphologies and chemical compositions of nanostructures. The image quality obtained by many current algorithms is seriously affected by the problems of missing wedge artefacts and non-linear projection intensities due to diffraction effects. The former refers to the fact that data cannot be acquired over the full 180° tilt range; the latter implies that for some orientations, crystalline structures can show strong contrast changes.

A new algorithm for 3D reconstruction from support functions.

We introduce a new algorithm for reconstructing an unknown shape from a finite number of noisy measurements of its support function. The algorithm, based on a least squares procedure, is very easy to program in standard software such as Matlab, and it works for both 2D and 3D reconstructions (in fact, in principle, in any dimension). Reconstructions may be obtained without any pre- or post-processing steps and with no restriction on the sets of measurement directions except their number, a limitation dictated only by computing time.

D-cycloserine potentiates the reconsolidation of cocaine-associated memories.

Conditioned cue-induced relapse to drug seeking is a major challenge to the treatment of drug addiction. It has been proposed that D-cycloserine might be useful in the prevention of relapse by reducing the conditioned reinforcing properties of drug-associated stimuli through facilitation of extinction. Here we show that intrabasolateral amygdala infusions of D-cycloserine in fact potentiate the reconsolidation of stimulus-cocaine memories to increase cue-induced relapse to drug seeking in rats with an extensive drug self-administration history.