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Approaches to control basal ganglia neural activity in real-time are needed to clarify the causal role of 13-35 Hz ("beta band") oscillatory dynamics in the manifestation of Parkinson's disease (PD) motor signs. Here, we show that resonant beta oscillations evoked by electrical pulses with precise amplitude and timing can be used to predictably suppress or amplify spontaneous beta band activity in the internal segment of the globus pallidus (GPi) in the human. Using this approach, referred to as closed-loop evoked interference deep brain stimulation (eiDBS), we could suppress or amplify frequency-specific (16-22 Hz) neural activity in a PD patient. Our results highlight the utility of eiDBS to characterize the role of oscillatory dynamics in PD and other brain conditions, and to develop personalized neuromodulation systems.

In the emergency department, there are infrequent but essential procedures related to pulmonary diseases that emergency physicians must be able to perform. These include thoracentesis, chest tube thoracostomy, tracheostomy manipulation, and fiberoptic intubation.

The purpose of this study was to biomechanically assess superior stability, subacromial contact pressures, and glenohumeral kinematics of a V-shaped anterior cable reconstruction with semitendinosus allograft (VST) in a massive rotator cuff tear (MCT) model.Eight cadaveric shoulders (mean age, 66 years; range, 48 to 72 years) were tested with a custom testing system used to evaluate superior translation, subacromial contact pressure, and glenohumeral kinematics at 0°, 20°, and 40° glenohumeral abduction and 0°, 30°, 60°, and 90° of external rotation (ER). Conditions tested included (1) native state, (2) MCT (complete supraspinatus and ½ infraspinatus), a (3) VST. The VST was secured medially on the glenoid with 1 anchor and on the greater tuberosity with a double-row configuration using 4 anchors.The VST significantly decreased superior translation compared to the MCT at 0° and 20° glenohumeral abduction for 0°, 30°, and 60° humeral rotation and at 40° abduction and 0° degrees humeral rotation (P.05). Superior translation following the VST remained significantly greater than the intact state at 0° abduction and 60° and 90° ER (P = .039 and 0.007, respectively) and 20° abduction and 30°, 60°, and 90° ER (P = .048, .003, and .004, respectively). The VST restored peak subacromial contact pressure to intact levels for all positions except 40° abduction and 60° ER. The VST did not statistically affect humeral head kinematics compared to the intact condition.In a biomechanical model, a VST anterior cable reconstruction partially restores superior stability and reduces peak subacromial contact pressure associated with an MCT, without affecting glenohumeral kinematics. The technique may be a consideration in the treatment of an irreparable MCT with isolated anterior cable disruption.The VST may provide an option for treatment of irreparable MCTs with anterior rotator cable disruption.

This paper presents a stabilization technique for the finite element modelling of contact-impact problems of elastic bars via a bi-penalty method for enforcing contact constraints while employing an explicit predictor–corrector time integration algorithms. The present proposed method combines three salient features in carrying out explicit transient analysis of contact-impact problems: the addition of a penalty term associated with a kinetic energy expression of gap constraints, in addition to the conventional internal energy penalty term of the gap constraints; an explicit integration method that alleviates spurious oscillations; and, a judicious selection of two penalty parameters such that the stable time steps of the resulting explicit method is least compromised. Numerical experiments have been carried out with three explicit methods: the standard central difference method, the stabilized predictor–corrector method (Wu, 2003 [50] ) and a method for mitigating spurious oscillations (Park et al., 2012 [44] ) as applied to simulate one-dimensional contact-impact problems of the Signorini problem and the impact of two elastic bars. Results indicate that the proposed method can maintain the contact-free stability limit of the central difference and yield improved accuracy compared with existing bi-penalty methods.

Purpose Achieving competency as educators is increasingly recognized as a critical part of residents’ training in graduate medical education across specialties. In addition to teaching medical students, radiation oncology residents often play a vital role in peer and interprofessional education. We conducted a survey to identify the needs of radiation oncology residents for developing skills in teaching. Methods and Materials An anonymous, web-based survey was developed and distributed to resident physicians at US radiation oncology programs. Analyses describe respondent demographics, experiences with teaching, and interest in various aspects of a formal “residents-as-teachers” curriculum. Results There were 171 completed survey responses (27.5% response rate). A total of 146 residents (85.4%) reported receiving no formal training in teaching before residency, and 121 (70.8%) reported no formal training during residency. Residents who had formal training in teaching were significantly more likely to be “quite” or “extremely” confident about teaching compared with residents who had no prior formal training (76.0% vs 51.4%; P = .022). Residents most commonly taught other residents and medical students (163 [95.3%] and 160 [93.6%] respondents, respectively). The most common settings for teaching were one-on-one teaching (164 respondents [95.9%]), small-group lectures (135 respondents [78.9%]), and intradepartmental lectures (136 respondents [79.5%]). In response to open-ended questions regarding desired teaching opportunities and domains for teaching development, many residents expressed a lack of confidence in teaching and were interested in improvement across many aspects of teaching. Conclusions Radiation oncology residents are expected and desire to teach in a multitude of settings across a wide variety of audiences. However, a significant proportion of radiation oncology residents lack formal training and rarely receive feedback for their teaching skills. The results of this national survey support the development of a residents-as-teachers curriculum for radiation oncology residents that would address the needs for and significant interest in this area.

Background The biomechanical relationship between irreparable rotator cuff tear size and glenohumeral joint stability in the setting of superiorly directed forces has not been characterized. The purpose of this study was to quantify kinematic alterations of the glenohumeral joint in response to superiorly directed forces in a progressive posterosuperior rotator cuff tear model. Methods Nine fresh-frozen cadaveric shoulders (mean age; 58 years) were tested with a custom shoulder testing system. Three conditions were tested: intact, stage II (supraspinatus) tear, stage III (supraspinatus + anterior half of infraspinatus) tear. At each condition, range of motion and humeral head positions were measured with a “balanced” loading condition, and with a superiorly directed force (“unbalanced loading condition”). At each of the 0°, 20°, and 40° of glenohumeral abduction positions, all measurements were made at 0°, 30°, 60°, and 90° of external rotation (ER). Two-way repeated measures analysis of variance with Tukey post hoc tests were performed for statistical analyses. Results With the balanced load, no significant change in superior humeral head position was observed in stage II tears. Stage III tears significantly changed the humeral head position superiorly at 30° and 60° ER at each abduction angle compared with the intact condition (P ≤ .028). With superiorly directed load, stage II and stage III tears both showed statistically significant increases in superior translation at all degrees of ER for all degrees of abduction (P ≤ .035), except stage II tears at 0° ER and 40° abduction (P = .185) compared with the intact condition. Stage II tears showed posterior translations with 30° and 60° ER, both at 20° and 40° of abduction. Stage III tears also showed posterior translations with 90° ER for all abduction angles (P ≤ .039). Conclusion With superiorly directed loads, complete supraspinatus tendon tears created superior translations at all abduction angles, and posterior instability in the middle ranges of rotation for 20° and 40° of abduction. Larger tears involving the anterior half of the infraspinatus tendon caused significant superior and posterior translations within the middle ranges of ER for all abduction angles. In addition to superior instability, posterior translation should be considered when selecting or developing surgical techniques for large posterosuperior rotator cuff tears.

We evaluated whether self-reports of worse cognition in older adults with normal cognitive function reflected actual memory decline, amyloid pathology, and subtle vulnerabilities in hippocampal function. We measured subjective cognitive decline (SCD) in 156 older participants from the Dallas Lifespan Brain Study. Functional hippocampal activation during encoding, measured with fMRI, and longitudinal memory change that was measured in the four years preceding the SCD measures were used to predict the magnitude of SCD. A subsample (N=105) also underwent 18F-Florbetapir PET imaging that measured amyloid burden. Results showed that increased SCD were associated with greater prior memory decline and amyloid deposition. Importantly, decreased hippocampal activation during encoding was a significant predictor of SCD, particularly in young-old adults below 69 years old, above and beyond prior memory change and amyloid deposition. These results indicate that multiple measures of neural and cognitive dysfunction are simultaneously associated with SCD. Moreover, SCD in younger seniors appears to reflect deficient hippocampal activity that increases their reports of poorer memory, independent of amyloid. This manuscript is part of the Special Issue entitled "Cognitive Neuroscience of Healthy and Pathological Aging" edited by Drs. M. N. Rajah, S. Belleville, and R. Cabeza. This article is part of the Virtual Special Issue titled COGNITIVE NEU-ROSCIENCE OF HEALTHY AND PATHOLOGICAL AGING. The full issue can be found on ScienceDirect at https://www.sciencedirect.com/journal/neurobiology-of-aging/special-issue/105379XPWJP.

The otolaryngologist – head and neck surgeon plays a unique role in the acute management of partial airway obstruction due to their familiarity with the surgical instruments and technical skills in establishing both nonsurgical and surgical airway access. When a partial airway obstruction deteriorates into impending or sudden airway loss, the surgeon must work intimately with the anesthesiologist and supporting staff to promptly establish an airway to minimize the injuries associated with prolonged hypoxia. The following article describes the surgical and operative techniques available to the otolaryngologist and an adapted airway algorithm for the impending or sudden loss of airway. The surgeon should become facile with these techniques in order to swiftly establish an airway in these emergency situations while minimizing complications and injury.

Recent studies have questioned the relative benefit of radiotherapy (RT) for older patients with favorable breast cancer given the lack of survival benefit and marginal local control benefit. Despite the 2004 National Comprehensive Cancer Network (NCCN) guidelines advocating for the option of hormonal therapy alone, trends in utilization rates of RT in this group are not well-documented. We analyzed our institutional experience with implementation of the guidelines over time.We identified 564 patients aged ≥ 60 years with favorable breast cancer treated with breast conserving surgery from 2000 to 2017. Patients met criteria for Cancer and Leukemia Group B (CALGB) 9343, Postoperative Radiotherapy in Minimum Risk Elderly (PRIME II), or the very-low risk cohort identified in the Toronto-British Columbia study. Multivariable logistic regression analysis was performed to assess the magnitude of association between omission status, grade, and tumor size while controlling for age and year of diagnosis.Overall RT omission rates were 17.6% prior to the 2004 NCCN update and 45% after the publication of the 10-year CALGB data in 2013. The overall RT omission rate was 29%. Patients with grade 1 to 2 histology (odds ratio, 3.2; 95% confidence interval, 1.3-7.7; P = .01) and tumors 1 cm (odds ratio, 1.60; 95% confidence interval, 0.4-0.9; P = .007) were more likely to omit RT than those with higher grade or larger tumors.We observed a slight decrease in the use of RT over time, suggesting a move towards adoption of the NCCN guidelines. There remains a fundamental need to continue to individualize breast cancer care based on risk stratification and make evidenced-based treatment recommendations with equitable use of health care resources.

The flicker electroretinogram (ERG) is typically analyzed in terms of peak-to-trough amplitude and implicit time. However, additional important information may be captured by spectral-domain analysis of the ERG harmonics (responses that occur at multiples of the stimulus frequency). This study describes an approach to analyze the harmonic components of the flicker ERG and its application to patients who have early-stage non-proliferative diabetic retinopathy (NPDR). Of particular interest were the sub-harmonic components occurring at 1.5x and 2.5x the stimulus frequency that produce cycle-to-cycle variation in amplitude termed “period doubling.” Twenty visually-normal subjects, 20 diabetic subjects who have no clinically-apparent retinopathy (NDR), and 20 diabetic subjects who have mild NPDR participated. ERGs were recorded in response to sinusoidal flicker (27–63 Hz) and Fourier analysis was performed to extract fundamental and harmonic response amplitudes. Linear quantile mixed models (LQMMs) were used to compare the amplitude of the response components among the three subject groups. Results indicated that the maximum sub-harmonic amplitude occurred in the stimulus frequency range of 33–38 Hz for all subjects. The LQMMs showed a significant sub-harmonic amplitude reduction for the mild NPDR subjects compared to the controls; sub-harmonic amplitude for the NDR subjects did not differ significantly from the controls. In contrast, the fundamental response did not differ among the groups for stimulus frequencies between 33 and 38 Hz. Modeling these results indicated that subharmonic amplitude loss in mild NPDR subjects may be attributed to attenuated feedback occurring early in the retina, possibly at the synapse of cone photoreceptors and OFF bipolar cells.

Purpose To evaluate the effect of setup uncertainties including uncertainties between different breath holds (BH) and inter-fractional anatomical changes under CT-guided BH with intensity-modulated proton therapy (IMPT) in patients with liver cancer. Methods and materials This retrospective study considered 17 patients with liver tumors who underwent feedback-guided BH (FGBH) IMRT treatment with daily CT-on-rail imaging. Planning CT images were acquired at simulation using FGBH, and FGBH CT-on-rail images were also acquired prior to each treatment. Selective robust IMPT plans were generated using planning CT and re-calculated on each daily CT-on-rail image. Subsequently, the fractional doses were deformed and accumulated onto the planning CT according to the deformable image registration between daily and planning CTs. The doses to the target and organs at risk (OARs) were compared between IMRT, planned IMPT, and accumulated IMPT doses. Results For IMPT plans, the mean of D98% of CTV for all 17 patients was slightly reduced from the planned dose of 68.90 ± 1.61 Gy to 66.48 ± 1.67 Gy for the accumulated dose. The target coverage could be further improved by adjusting planning techniques. The dose–volume histograms of both planned and accumulated IMPT doses showed better sparing of OARs than that of the IMRT. Conclusions IMPT with FGBH and CT-on-rail guidance is a robust treatment approach for liver tumor cases.

Presented in this paper is a modeling formalism for the energy simulation of conveyor systems. Reducing the energy consumption of a conveyor system can decrease a significant portion of the operation cost, contribute to the sustainable operation, and prepare for future energy cost increases related to regulations for green industry. Therefore, the energy consumption is becoming one of the key performance indicators in conveyor systems design. To construct a simulation model considering the energy consumption of conveyor systems, the modeling formalism is necessary to represent the multiple material transportations and conveyor operation switching (on and off) depending on material load states. This paper proposes a new modeling formalism satisfying the requirements by extending the conventional discrete event system specification (DEVS) formalism. In the proposed formalism, each simulation entity has an energy model, which is derived from the reverse engineering of real conveyor operations, to determine energy consumption states and rates. The simulation results of this research have been applied to the revision of a warehouse conveyor system in Korea.

Jet energy transported to quark-gluon plasma during jet-medium interaction excites the QGP medium and creates energetic thermal partons – recoil particles or recoils. Modification of the jet structure in heavy ion collisions is studied using martini, in which recoil simulation is enabled. In large systems such as central Pb-Pb collisions, the recoil effect is expected to be critical due to strong jet-medium interaction. We show the results of the jet mass function and jet shape function are improved when the recoil particles are included in the reconstructed jets. We conclude that the energy carried by the recoil particles are regarded as a part of reconstructed jets and are necessary in studying jet modification in heavy ion collisions.