Asymptotics of a Double Integral Vălean, Cornel Ioan; Andersen, Kenneth F.
The American mathematical monthly,
06/2019, Letnik:
126, Številka:
6
Journal Article
Purpose
Persistent pain is a known challenge among breast cancer survivors. In secondary analyses of a randomized controlled trial, we examined the effect of progressive resistance training on ...persistent pain in the post-operative year in women treated for breast cancer with axillary lymph node dissection.
Methods
We randomized 158 women after BC surgery with Axillary Lymph Node Dissection (ALND) (1:1) to usual care or a 1-year, supervised and self-administered, progressive resistance training intervention initiated 3 weeks after surgery. A questionnaire at baseline, 20 weeks and 12 months assessed the intensity and frequency of pain, neuropathic pain and influence of pain on aspects of daily life. We analysed the effect using linear mixed models and multinomial logistic regression models for repeated measures.
Results
A high percentage of participants experienced baseline pain (85% and 83% in the control and intervention groups respectively) and by the 12 month assessment these numbers were more than halved. A high proportion of participants also experienced neuropathic pain (88% and 89% in control and intervention group respectively), a finding that was stable throughout the study period. The effect on intensity of pain indicators favoured the exercise group, although most estimates did not reach statistical significance, with differences being small.
Conclusion
For women who had BC surgery with ALND, our progressive resistance training intervention conferred no benefit over usual care in reducing pain. Importantly, it did not increase the risk of pain both in the short and long term rehabilitative phase.
Quantitative sensory testing (QST) is used to assess sensory dysfunction and nerve damage by examining psychophysical responses to controlled, graded stimuli such as mechanical and thermal detection ...and pain thresholds. In the breast cancer population, 4 studies have used QST to examine persistent pain after breast cancer treatment, suggesting neuropathic pain being a prominent pain mechanism. However, the agreement and reliability of QST has not been described in the postsurgical breast cancer population, hindering exact interpretation of QST studies in this population. The aim of the present study was to assess test-retest properties of QST after breast cancer surgery.
A total of 32 patients recruited from a larger ongoing prospective trial were examined with QST 12 months after breast cancer surgery and reexamined a week later. A standardized QST protocol was used, including sensory mapping for mechanical, warmth and cold areas of sensory dysfunction, mechanical thresholds using monofilaments and pin-prick, thermal thresholds including warmth and cold detection thresholds and heat pain threshold, with bilateral examination. Agreement and reliability were assessed by Bland-Altman plots, descriptive statistics, coefficients of variance, and intraclass correlation.
Bland-Altman plots showed high variation on the surgical side. Intraclass coefficients ranged from 0.356 to 0.847 (moderate to substantial reliability). Between-patient variation was generally higher (0.9 to 14.5 SD) than within-patient variation (0.23 to 3.55 SD). There were no significant differences between pain and pain-free patients. The individual test-retest variability was higher on the operated side compared with the nonoperated side.
The QST protocol reliability allows for group-to-group comparison of sensory function, but less so for individual follow-up after breast cancer surgery.
New ultrasound imaging and therapeutic modalities may require transducer designs that are not readily facilitated by conventional design guidelines and analytical expressions. This motivates the ...investigation of numerical methods for complex transducer structures. Based on a mathematical theorem, we propose a new numerical design and optimization method for ultrasound transducers by linearizing the phase spectrum of transducer transfer functions. A gradient-based algorithm obtains the optimal transducer by varying a selected set of transducer parameters. To demonstrate the linear phase method, a simulated air-backed 4-MHz single-element imaging transducer with two matching layers, bondlines, and electrodes is optimized by varying the impedances and thicknesses of the matching layers. The magnitude spectrum resembles that of a Gaussian and, compared to a conventional transducer, the time-sidelobe level is reduced by more than 15-dB. Moreover, we apply the linear phase method to analyze and compensate for bondlines that resonate within the passband. Finally, we address the challenge of obtaining materials for the matching layers with the optimized impedance values by calculating alternative material pairs.
Persistent pain after breast cancer treatment (PPBCT) affects 25% to 60% of breast cancer survivors and is recognized as a clinical problem, with 10% to 15% reporting moderate to severe pain several ...years after treatment. Psychological comorbidity is known to influence pain perception, and evidence links signs of depression and anxiety with development of PPBCT. The purpose of this study was to assess preoperative distress as a predictive factor for development of PPBCT.
Between October 2008 and October 2009, 426 women diagnosed with primary breast cancer, undergoing surgery at the Department of Breast Surgery, Rigshospitalet, Denmark, were invited to participate in the study. Patients filled out a questionnaire preoperatively, and 4 and 8 months after surgery. Preoperative distress was measured with the Distress Thermometer (DT; 11-point scale, 0-10). We examined the association between severe preoperative distress (using DT ≥7) and moderate to severe PPBCT 8 months after diagnosis using a logistic regression model.
A total of 357 patients participated in this study and 291 (82%) returned all follow-up questionnaires. Preoperative distress was significantly associated with moderate to severe PPBCT at 8 months, with an adjusted odds ratio (OR) of 2.05 (95% CI, 1.18-3.59; P=.01), and at 4 months, with an OR of 2.23 (95% CI, 1.23-4.05; P=.01).
Preoperative distress was associated with PPCBT, suggesting distress as an independent risk factor for PPBCT. Preoperative identification of patients at risk for PPBCT allows for further research in psychological and pharmacological treatment of this condition.
A Dual-Frequency Coupled Resonator Transducer Andersen, Kenneth Kirkeng; Frijlink, Martijn E.; Johansen, Tonni Franke ...
IEEE transactions on ultrasonics, ferroelectrics, and frequency control,
10/2020, Letnik:
67, Številka:
10
Journal Article
Recenzirano
New ultrasound-mediated drug delivery systems, such as acoustic cluster therapy or combined imaging and therapy systems, require transducers that can operate beyond the bandwidth limitation (~100%) ...of conventional piezoceramic transducers. In this article, a dual-frequency coupled resonator transducer (CRT) comprised of a polymeric coupling layer with a low acoustic impedance (2-5 MRayl) sandwiched between two piezoceramic layers is investigated. Depending on the electrical configuration, the CRT exhibits two usable frequency bands. The resonance frequency of the high-frequency (HF) band can be tailored to be ~3-5 times higher than that of the low-frequency (LF) band using the stiffness in the coupling layer. The CRT's LF band was analyzed analytically, and we obtained the closed-form expressions for the LF resonance frequency. A dual-frequency CRT was designed, manufactured, and characterized acoustically, and comparisons with theory showed good agreement. The HF band exhibited a center frequency of 2.5 MHz with a −3-dB bandwidth of 70% and is suited to manipulate microbubbles or for diagnostic imaging applications. The LF band exhibited a center frequency of 0.5 MHz with a −3-dB bandwidth of 13% and is suited to induce biological effects in tissue, therein manipulation of microbubbles.
Objective To examine the development of persistent pain after treatment for breast cancer and to examine risk factors associated with continuing pain. Design Repeated cross sectional study in a ...previously examined nationwide cohort. All eligible women who underwent surgery for primary breast cancer in Denmark in 2005 and 2006 and were examined in 2008 were surveyed again with the same questionnaire.Setting Surgical centres in Denmark.Main outcome measures Prevalence, location, and severity of persistent pain after treatment for breast cancer in well defined treatment groups and changes in pain reporting and sensory disturbances from 2008 to 2012.Participants In 2012, 2828 women were eligible in our database, and 108 were excluded. Exclusion criteria were death; new, recurrent, or other cancer; reconstructive breast surgery; and emigration. Results 2411 (89%) women returned the questionnaire. Prevalence of persistent pain after treatment for breast cancer ranged from 22% to 53% depending on treatment. In 2012, 903 (37%) women reported such pain, a fall from 45% in 2008. Of these, 378 (16%) reported pain of ≥4 on a numerical rating scale (scale 0-10), a fall from 19%. Among women reporting pain in 2008, 36% no longer reported it in 2012. In contrast, 15% of the women who did not report pain in 2008 reported it in 2012. Risk factors for having pain were axillary lymph node dissection rather than sentinel lymph node biopsy (odds ratio 2.04, 95% confidence interval 1.60 to 2.61; P<0.001) and age ≤49 (1.78, 1.25 to 2.54; P<0.001). No particular method of treatment or age was associated with an increase in pain from 2008 to 2012.Conclusions Persistent pain after treatment for breast cancer remains an important problem five to seven years later. The problem is not static as it can either progress or regress with time. Trial registration Clinicaltrials.gov NCT No 01543711.
Sequelae such as pain, sensory disturbances and psychological distress are well known after treatment for invasive breast cancer (IBC). Patients treated for ductal carcinoma in situ (DCIS) receive a ...similar treatment as low-risk IBC. The aim of this cross-sectional study was to describe prevalence of postoperative pain, sensory disturbances, psychological distress and rehabilitation needs among Danish women with DCIS.
A total of 574 women treated for DCIS in Denmark in 2013 and 2014 were enrolled and 473 (82%) completed a detailed questionnaire on demographic factors, pain, sensory disturbances, psychological aspects and rehabilitation needs 1-3 years after surgery.
Median age was 60 years. A total of 33% of patients reported any pain and 12% reported moderate to severe pain in the area of surgery. Younger age (<50 years OR 4.7 (95% CI: 1.6-14.0, p = 0.006)), aged 50 to 65 years OR 2.8 (95% CI: 1.1-7.0, p = 0.02) and anxiety and depression (measured by HADS
>15 OR of 3.1 (95% CI: 1.5-6.3, p = 0.003)) were significantly associated with moderate to severe pain. Approximately one-third of the patients reported sensory disturbances such as pins and needles (32%), numbness (37%) and painful itch (30%) and 94 women (20%) reported anxiety ≥8, 26 (6%) depression and 51 (11%) reported distress.
This cross-sectional study showed that women treated for DCIS suffered from pain, sensory disturbances and psychological impairment and had unmet rehabilitation needs. Further research is warranted, specifically addressing rehabilitation after diagnosis and treatment of DCIS.
A large body of research exists investigating the link between environmental attitudes and behavior. Many empirical studies have found modest positive effects, suggesting that attitudes toward the ...environment might indeed influence environmental behavior. However, most of the previous empirical work is cross-sectional and correlational in nature. This means that the issue of the causal effect of environmental attitudes on behavior is far from settled, and that the relationships observed in the past may be due to unobserved confounders. In a panel study using six waves of the GESIS Panel Survey, we examine the individual-level effect of changes in one’s attitudes on changes in different forms of environmental behavior. We use fixed effects panel regression within the structural equation modeling framework to control for unobserved time-invariant confounders, while also tackling other methodological challenges. We find that environmental attitudes have no effect on behavior after controlling for unobserved confounders. However, there is a robust effect of attitudes on willingness to sacrifice. This suggests that creating more positive attitudes might make individuals more willing to accept sacrifices for environmental protection.
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