Angular dependence of novel magnetic quantum oscillations in a quasi-two-dimensional multiband Fermi liquid with impurities

The semiclassical Lifshitz-Kosevich-type description is given for the angular dependence of quantum oscillations with combination frequencies in a multiband quasi-two-dimensional Fermi liquid with a constant number of electrons. The analytical expressions are found for the Dingle, thermal, spin, and amplitude (Yamaji) reduction factors of the novel combination harmonics, where the latter two strongly oscillate with the direction of the field. At the "magic" angles those factors reduce to the purely two-dimensional expressions given earlier. The combination harmonics are suppressed in the presence of the non-quantized ("background") states, and they decay exponentially faster with temperature and/or disorder compared to the standard harmonics, providing an additional tool for electronic structure determination. The theory is applied to Sr$_2$RuO$_4$.Comment: 5 pages, 2 figures, minor typos correcte

1, 2, 3, 4: Infusing Quantitative Literacy into Introductory Biology

Biology of the twenty-first century is an increasingly quantitative science. Undergraduate biology education therefore needs to provide opportunities for students to develop fluency in the tools and language of quantitative disciplines. Quantitative literacy (QL) is important for future scientists as well as for citizens, who need to interpret numeric information and data-based claims regarding nearly every aspect of daily life. To address the need for QL in biology education, we incorporated quantitative concepts throughout a semester-long introductory biology course at a large research university. Early in the course, we assessed the quantitative skills that students bring to the introductory biology classroom and found that students had difficulties in performing simple calculations, representing data graphically, and articulating data-driven arguments. In response to students' learning needs, we infused the course with quantitative concepts aligned with the existing course content and learning objectives. The effectiveness of this approach is demonstrated by significant improvement in the quality of students' graphical representations of biological data. Infusing QL in introductory biology presents challenges. Our study, however, supports the conclusion that it is feasible in the context of an existing course, consistent with the goals of college biology education, and promotes students' development of important quantitative skills

RETRATO DE SEÑOR [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

The Reliability of Determining the Presence of Surgical Site Infection Based on Retrospective Chart Review

Purpose Surgical site infection (SSI) can be a challenging complication after hand surgery. Retrospective studies often rely on chart review to determine presence of an SSI. The purpose of this study was to assess reliability of Centers for Disease Control and Prevention (CDC) criteria for determining an SSI as applied to a chart review. We hypothesized that interobserver and intraobserver reliability for determining an SSI using these criteria while reviewing medical record documentation would be none to minimal (k < 0.39) based on an interpretation of Cohen’s k statistics. Methods We created and used a database of 782 patients, 48 of whom received antibiotics within 3 months of a surgical procedure of the hand. Three fellowship-trained orthopedic hand surgeons then evaluated the charts of those 48 patients, in which each reviewer determined whether an SSI was present or absent based on CDC criteria provided to the reviewers. Patients’ charts were then reassessed 1 month later by the same reviewers. Kappa statistics were calculated for each round of assessment and averaged to determine intraobserver and interobserver reliability. Results Overall k values were 0.22 (standard error, 0.13), indicating fair reliability. Average k value between reviewers was 0.26 (standard error, 0.13. On average, intrarater reliability was 68.7%. Conclusions We found poor interobserver and intraobserver reliability when using CDC criteria to determine whether a patient had an SSI, based on chart review

Nonsurgical Providers Provide the Majority of Postoperative Opioid Prescriptions After Hand Surgery.

Introduction The increased use of Prescription Drug Monitoring Program (PDMP) websites has helped physicians to limit overlapping controlled substance prescriptions and help prevent opioid abuse. Many studies have investigated risk factors for prolonged opioid use after orthopedic surgery, but few studies have investigated who is prescribing opioids to postoperative patients. The purpose of this study is to investigate the types of medical providers prescribing opioids to hand surgery patients postoperatively. Methods Institutional Review Board approval was obtained prior to initiation of this study. An institutional database search was performed to identify all patients ≥18 years old that underwent a single hand surgery at our institution during a specified time period. Patients with more than one surgical procedure during this time were excluded to prevent potential crossover with opioid prescriptions for different surgical procedures. A search of the state PDMP website was performed to identify opioid prescriptions filled by hand surgery patients from six months preoperatively to 12 months postoperatively. Opioid prescribers were classified into several groups: 1) the patient\u27s operating surgeon, 2) other orthopedic surgery providers, 3) general medicine providers (internal medicine, primary care, family medicine, and adult health providers), and 4) all other medical providers. Results Three hundred twenty-seven patients could be identified in the PDMP database who received an opioid prescription on the day of surgery. Of these, 108 (33.0%) filled a total of 341 additional opioid prescriptions postoperatively. Non-orthopedic providers prescribed 81.5% of all opioid prescriptions within 12 months postoperatively, with the patient\u27s operating surgeon prescribing only 10% of all prescriptions. General medicine providers were the highest prescriber group at 28.7% of total postoperative opioid prescriptions. From six to 12 months postoperatively, the patient\u27s operating surgeon prescribed only 4.9% of total opioid prescriptions filled. The patient\u27s operating surgeon prescribed significantly smaller average opioid prescriptions in total morphine milligram equivalents compared to all other provider groups. Conclusions Surgeons should be aware that their surgical patients may be receiving opioid prescriptions from a wide variety of medical providers postoperatively, and that these other providers may be prescribing larger prescriptions. The findings of this study emphasize the importance of collaboration across medical specialties to mitigate the risks of prolonged opioid use after hand surgery

Wound Dehiscence Following Cubital Tunnel Surgery.

PURPOSE: Cubital tunnel syndrome is the second most common upper-extremity compressive neuropathy, and persistent symptoms can necessitate operative treatment. Surgical options include simple decompression and ulnar nerve transposition. The cause of wound dehiscence after surgery is not well known, and the factors leading to the development of these complications have not been previously described. METHODS: Patients undergoing ulnar nerve surgery from January 1, 2016, to December 31, 2019, were retrospectively evaluated for the development of wound dehiscence within 3 months of surgery. There were 295 patients identified who underwent transposition and 1,106 patients who underwent simple decompression. Patient demographics and past medical history were collected to evaluate the risk factors for the development of wound dehiscence. RESULTS: The overall rate of wound dehiscence following surgery was 2.5%. In the simple decompression group, the rate of wound dehiscence was 2.7% (30/1,106), which occurred a mean of 21 days (range, 2-57 days) following surgery. In the transposition group, the rate of wound dehiscence was 1.7% (5/295), which occurred a mean of 20 days (range, 12-32 days) following surgery. The difference in rates of dehiscence between the decompression and transposition groups was not significant. Five patients in the simple decompression group and 1 patient in the transposition group required a secondary surgery for closure of the wound. Age, body mass index, smoking status, and medical comorbidities were not found to contribute to the development of wound dehiscence. CONCLUSIONS: Wound dehiscence can occur following both simple decompression and transposition, even after postoperative evaluation demonstrates a healed wound. Surgeons should be aware of this possibility and specifically counsel patients about remaining cautious with, and protective of, their wound for several weeks after surgery. Dehiscence may be related to suboptimal vascularity in the soft tissue envelope in the posteromedial elbow. When it occurs, dehiscence can generally be treated by allowing healing by secondary intention. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV

Patient-Reported Disability Measures Do Not Correlate with Electrodiagnostic Severity in Carpal Tunnel Syndrome

Background:. Electrophysiologic studies including electromyography and nerve conduction studies play a role in the evaluation of carpal tunnel syndrome (CTS), despite evidence that these studies do not correlate with CTS-specific symptom scores. There is a lack of evidence comparing electrophysiologic data with general measures of function. Methods:. Fifty patients presenting for CTS treatment over an 8-month period were analyzed retrospectively. All patients completed surveys including the Quick Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH) and the Medical Outcomes Study 12-Item Short-Form Survey [(physical component summary 12, mental component summary (MCS-12)]. Electromyography and nerve conduction studies were performed on all patients and compared with outcome scores. Results:. Analysis demonstrated no relationship between DASH or MCS-12 and electrodiagnostic severity. No significant correlations were noted between DASH or MCS-12 and median motor or sensory latency. There was a moderate–weak correlation (rho = 0.34) between more severe electrophysiologic grade and better function based on physical component summary 12. Conclusions:. Electrodiagnostic severity grades do not correlate with patient-reported disability, including the DASH and MCS–12 surveys. There is a counterintuitive correlation between more-severe electrodiagnostic findings and decreased physical disability. These findings indicate that disability may not correlate with electrodiagnostic severity of median neuropathy in CTS

Prenatal and Neonatal Thyroid Stimulating Hormone Levels and Autism Spectrum Disorders

Thyroid hormones are critical for normal brain development. This study examined autism spectrum disorders (ASD) and thyroid stimulating hormone (TSH) levels measured in mid-pregnancy maternal serum and infant blood after birth. Three groups of children born in Orange County, CA in 2000-2001 were identified: ASD (n = 78), developmental delay (n = 45), and general population controls (GP) (n = 149). Samples were retrieved from prenatal and newborn screening specimen archives. Adjusted logistic regression models showed inverse associations between ASD and log transformed TSH levels in maternal serum samples (ASD vs. GP: OR [95 % CI] 0.33 [0.12-0.91], Early Onset ASD vs. GP: 0.31 [0.10-0.98]). Results for thyroid levels in newborn blood samples were similar though not significant (ASD vs. GP: 0.61 [0.18-2.04])