The spectral shift function and Levinson's theorem for quantum star graphs

We consider the Schr\"odinger operator on a star shaped graph with $n$ edges joined at a single vertex. We derive an expression for the trace of the difference of the perturbed and unperturbed resolvent in terms of a Wronskian. This leads to representations for the perturbation determinant and the spectral shift function, and to an analog of Levinson's formula

Molekularna dijagnostika i serološka istraživanja pestivirusa u ovaca.

In this research, the virological and serological presence of pestiviruses, such as border disease virus (BDV) was investigated in a sheep in the Central and Eastern Black Sea Regions of Turkey. The study material consisted of 40 organ materials collected from 13 aborted lambs, which were suspected to have pestiviruses, BDV and Bovine Viral Diarrhoea Virus (BVDV). Viral nucleic acids were investigated by using the reverse transcription polymerase chain reaction (RT-PCR). Nine of 13 aborted lambs (69.2%) and 24 of 40 organ samples (60%) obtained from those sheep were BDV RNA positive, whilst all the animals and organ samples were BVDV-RNA negative. Serum samples collected from 401 randomly selected sheep were investigated for pestivirus antibodies using competitive ELISA (cELISA) and the serum microneutralisation test (SNT) using BVDV-NADL strain. Seropositivity was found in between 7.22 and 74.38% with cELISA and 4.81 and 67.76% with SNT. Seropositivity rates in Amasya and Tokat provinces were higher than in Samsun and Giresun. The obtained data indicated that pestivirus infection in sheep is widespread in the Central and Eastern Black Sea Region.U radu su prikazana virološka i serološka istraživanja pestivirusa odnosno borderske bolesti u ovaca na središnjem i istočnom području Crnoga mora u Turskoj. Ukupno je bilo pretraženo 40 uzoraka tkiva različitih organa uzetih od 13 pobačenih plodova pod sumnjom da je uzročnik bio virus borderske bolesti ili virus virusnog proljeva goveda. Uzorci su bili pretraženi na prisutnost virusne nukleinske kiseline lančanom reakcijom polimerazom uz prethodnu reverznu transkripciju (RT-PCR). Devet od 13 pobačenih plodova (69,2%) i 24 od 40 uzoraka tkiva organa (60%) sadržavalo je RNA virusa borderske bolesti. Svi pretraženi uzorci bili su negativni na virus virusnoga proljeva. Uzorci seruma nasumce prikupljeni od 401 ovce bili su pretraženi na prisutnost specifičnih protutijela uporabom kompetitivnoga imunoenzimnoga testa (cELISA) i serum neutralizacijskoga testa (SNT) sa sojem NADL virusa virusnoga proljeva goveda. Ustanovljeno je da sepostotak serološki pozitivnih cELISA-om kretao od 7,22 do 74,38%, a SNT-om od 4,81 do 67,76%. Postotak serološki pozitivnih životinja u provincijama Amasya i Tokat bio je veći nego u provincijama Samsun i Giresun. Rezultati upućuju na zaključak da su pestivirusne zaraze rasprostranjene u ovaca na središnjem i istočnom području Crnoga mora

Effects of a Tailored Follow-Up Intervention on Health Behaviors, Beliefs, and Attitudes

Background: The high rates of relapse that tend to occur after short-term behavioral interventions indicate the need for maintenance programs that promote long-term adherence to new behavior patterns. Computer-tailored health messages that are mailed to participants or given in brief telephone calls offer an innovative and time-efficient alternative to ongoing face-to-face contact with healthcare providers. Methods: Following a 1-year behavior change program, 22 North Carolina health departments were randomly assigned to a follow-up intervention or control condition. Data were collected from 1999 to 2001 by telephone-administered surveys at preintervention and postintervention for 511 low-income, midlife adult women enrolled in the Well-Integrated Screening and Evaluation for Women Across the Nation (WISEWOMAN) program at local North Carolina health departments. During the year after the behavior change program, intervention participants were mailed six sets of computer-tailored health messages and received two computer-tailored telephone counseling sessions. Main outcomes of dietary and physical activity behaviors, beliefs, and attitudes were measured. Results: Intervention participants were more likely to move forward into more advanced stages of physical activity change (p = 0.02); control participants were more likely to increase their level of dietary social support at follow-up (p = 0.05). Both groups maintained low levels of reported saturated fat and cholesterol intake at follow-up. No changes were seen in physical activity in either group. Conclusions: Mailed computer-tailored health messages and telephone counseling calls favorably modified forward physical activity stage movement but did not appreciably affect any other psychosocial or behavioral outcomes

Renal replacement therapies in the aftermath of the catastrophic Marmara earthquake

Renal replacement therapies in the aftermath of the catastrophic Marmara earthquake.BackgroundRenal replacement therapy is of vital importance in the treatment of crush syndrome victims, who are frequently encountered after catastrophic earthquakes. The Marmara earthquake, which struck Northwestern Turkey in August 1999, was characterized by 477 victims who needed dialysis.MethodWithin the first week of the disaster, questionnaires containing 63 clinical and laboratory variables were sent to 35 reference hospitals that treated the victims. Information considering the features of dialyses obtained through these questionnaires was submitted to analysis.ResultsOverall, 639 casualties with renal complications were registered, 477 of whom (mean age 32.3 ± 13.7 years, 269 male) needed dialysis. Among these, 452 were treated by a single dialysis modality (437 intermittent hemodialysis, 11 continuous renal replacement therapy and 4 peritoneal dialysis), while 25 victims needed more than one type of dialysis. In total, 5137 hemodialysis sessions were performed (mean 11.1 ± 8.0 sessions per patient) and mean duration of hemodialysis support was 13.4 ± 9.0 days; this duration was shorter in the non-survivors (7.0 ± 8.7 vs. 10.0 ± 9.8 days, P = 0.005). Thirty-four victims who underwent continuous renal replacement therapy had higher mortality rates (41.2 vs. 13.7%, P < 0.0001). Only eight victims were treated by peritoneal dialysis, four of whom also required hemodialysis or continuous renal replacement therapy. The mortality rate in the dialyzed victims was 17.2%, a significantly higher figure compared to the mortality rate of the non-dialyzed patients with renal problems (9.3%; P = 0.015).ConclusionSubstantial amounts of dialysis support may be necessary for treating the victims of mass disasters complicated with crush syndrome. Dialyzed patients are characterized by higher rates of morbidity and mortality

Impelling Factors for Contracting COVID-19 Among Surgical Professionals During the Pandemic: A Multinational Cohort Study.

BACKGROUND Medical workers, including surgical professionals working in coronavirus disease 2019 (COVID-19) treating hospitals, were under enormous stress during the pandemic. This global study investigated factors endowing COVID-19 amongst surgical professionals and students. METHODS This global cross-sectional survey was made live on February 18, 2021 and closed for analysis on March 13, 2021. It was freely shared on social and scientific media platforms and was sent via email groups and circulated through a personal network of authors. Chi-square test for independence, and binary logistic regression analysis were carried out on determining predictors of surgical professionals contracting COVID-19. RESULTS This survey captured the response of 520 surgical professionals from 66 countries. Of the professionals, 92.5% (481/520) reported practising in hospitals managing COVID-19 patients. More than one-fourth (25.6%) of the respondents (133/520) reported suffering from COVID-19 which was more frequent in surgical professionals practising in public sector healthcare institutions (P = 0.001). Thirty-seven percent of those who reported never contracting COVID-19 (139/376) reported being still asked to practice self-isolation and wear a shield without the diagnosis (P = 0.001). Of those who did not contract COVID-19, 75.7% (283/376) were vaccinated (P < 0.001). Surgical professionals undergoing practice in the private sector (odds ratio (OR): 0.33; 95% confidence interval (CI): 0.14 - 0.77; P = 0.011) and receiving two doses of vaccine (OR: 0.55; 95% CI: 0.32 - 0.95; P = 0.031) were identified to enjoy decreased odds of contracting COVID-19. Only 6.9% of those who reported not contracting COVID-19 (26/376) were calculated to have the highest "overall composite level of harm" score (P < 0.001). CONCLUSIONS High prevalence of respondents got COVID-19, which was more frequent in participants working in public sector hospitals. Those who reported contracting COVID-19 were calculated to have the highest level of harm score. Self-isolation or shield, getting two doses of vaccines decreases the odds of contracting COVID-19

FDG-PET/MRI for nonoperative management of rectal cancer: A prospective pilot study

Nonoperative management (NOM) is increasingly utilized for rectal cancer patients with a clinical complete response (cCR) following total neoadjuvant therapy (TNT). The objective of this pilot study was to determine whether FDG-PET/MRI alters clinical response assessments among stage I-III rectal cancer patients undergoing TNT followed by NOM, relative to MRI alone. This prospective study included 14 subjects with new rectal cancer diagnoses. Imaging consisted of FDG-PET/MRI for initial staging, post-TNT restaging, and surveillance during NOM. Two independent readers assessed treatment response on MRI followed by FDG-PET/MRI. Inter-reader differences were resolved by consensus review. The reference standard for post-TNT restaging consisted of surgical pathology or clinical follow-up. 7/14 subjects completed post-TNT restaging FDG-PET/MRIs. 5/7 subjects had evidence of residual disease and underwent total mesorectal excision; 2/7 subjects had initial cCR with no evidence of disease after 12 months of NOM. FDG-PET/MRI assessments of cCR status at post-TNT restaging had an accuracy of 100%, compared with 71% for MRI alone, as FDG-PET detected residual tumor in 2 more subjects. Inter-reader agreement for cCR status on FDG-PET/MRI was moderate (kappa, 0.56). FDG-PET provided added value in 82% (9/11) of restaging/surveillance scans. Our preliminary data indicate that FDG-PET/MRI can detect more residual disease after TNT than MRI alone, with the FDG-PET component providing added value in most restaging/surveillance scans

Network Alterations in Comorbid Chronic Pain and Opioid Addiction: An Exploratory Approach

The comorbidity of chronic pain and opioid addiction is a serious problem that has been growing with the practice of prescribing opioids for chronic pain. Neuroimaging research has shown that chronic pain and opioid dependence both affect brain structure and function, but this is the first study to evaluate the neurophysiological alterations in patients with comorbid chronic pain and addiction. Eighteen participants with chronic low back pain and opioid addiction were compared with eighteen age- and sex-matched healthy individuals in a pain-induction fMRI task. Unified structural equation modeling (SEM) with Lagrange multiplier (LM) testing yielded a network model of pain processing for patient and control groups based on 19 a priori defined regions. Tests of differences between groups on specific regression parameters were determined on a path-by-path basis using z-tests corrected for the number of comparisons. Patients with the chronic pain and addiction comorbidity had increased connection strengths; many of these connections were interhemispheric and spanned regions involved in sensory, affective, and cognitive processes. The affected regions included those that are commonly altered in chronic pain or addiction alone, indicating that this comorbidity manifests with neurological symptoms of both disorders. Understanding the neural mechanisms involved in the comorbidity is crucial to finding a comprehensive treatment, rather than treating the symptoms individually