1,149 research outputs found
Band offsets in Si/Si1âxâyGexCy heterojunctions measured by admittance spectroscopy
We have used admittance spectroscopy to measure conduction-band and valence-band offsets in Si/Si1âxGex and Si/Si1âxâyGexCy heterostructures grown by solid-source molecular-beam epitaxy. Valence-band offsets measured for Si/Si1âxGex heterojunctions were in excellent agreement with previously reported values. Incorporation of C into Si1âxâyGexCy lowers the valence- and conduction-band-edge energies compared to those in Si1âxGex with the same Ge concentration. Comparison of our measured band offsets with previously reported measurements of energy band gaps in Si1âxâyGexCy and Si1âyCy alloy layers indicate that the band alignment is Type I for the compositions we have studied and that our measured band offsets are in quantitative agreement with these previously reported results
Measurement of band offsets in Si/Si1âxGex and Si/Si1âxâyGexCy heterojunctions
Realization of group IV heterostructure devices requires the accurate measurement of the energy band offsets in Si/Si1âxGex and Si/Si1âxâyGexCy heterojunctions. Using admittance spectroscopy, we have measured valence-band offsets in Si/Si1âxGex heterostructures and conduction-band and valence-band offsets in Si/Si1âxâyGexCy heterostructures grown by solid-source molecular-beam epitaxy. Measured Si/Si1âxGex valence-band offsets were in excellent agreement with previously reported values. For Si/Si1âxâyGexCy our measurements yielded a conduction-band offset of 100 ± 11 meV for a n-type Si/Si0.82Ge0.169C0.011 heterojunction and valence-band offsets of 118 ± 12 meV for a p-type Si/Si0.79Ge0.206C0.004 heterojunction and 223 ± 20 meV for a p-type Si/Si0.595Ge0.394C0.011 heterojunction. Comparison of our measured band offsets with previously reported measurements of energy band gaps in Si1âxâyGexCy and Si1âyCy alloy layers indicates that the band alignment is type I for the compositions we have studied and that our measured band offsets are in quantitative agreement with these previously reported results
Solid Microneedles for Transdermal Delivery of Amantadine Hydrochloride and Pramipexole Dihydrochloride
The aim of this project was to study the influence of microneedles on transdermal delivery of amantadine hydrochloride and pramipexole dihydrochloride across porcine ear skin in vitro. Microchannel visualization studies were carried out and characterization of the microchannel depth was performed using confocal laser scanning microscopy (CLSM) to demonstrate microchannel formation following microneedle roller application. We also report, for the first time, the use of TA.XT Plus Texture Analyzer to characterize burst force in pig skin for transdermal drug delivery experiments. This is the force required to rupture pig skin. The mean passive flux of amantadine hydrochloride, determined using a developed LCâMS/MS technique, was 22.38 ± 4.73 ÎŒg/cm2/h, while the mean flux following the use of a stainless steel microneedle roller was 49.04 ± 19.77 ÎŒg/cm2/h. The mean passive flux of pramipexole dihydrochloride was 134.83 ± 13.66 ÎŒg/cm2/h, while the flux following the use of a stainless steel microneedle roller was 134.04 ± 0.98 ÎŒg/cm2/h. For both drugs, the difference in flux values following the use of solid stainless steel microneedle roller was not statistically significantly (p \u3e 0.05). Statistical analysis was carried out using the MannâWhitney Rank sum test
Healthcare providersâ perceptions of socioeconomically disadvantaged patients with chronic pain: A qualitative investigation
Socioeconomically disadvantaged individuals are at-risk for chronic pain and disparate care. In this qualitative study, we explored providersâ experiences with socioeconomically disadvantaged patients, with a particular focus on providersâ: (1) perceptions of socioeconomically disadvantaged patientsâ barriers to pain care, (2) attitudes towards this patient population, and (3) chronic pain decisions for these patients. Individual interviews were conducted with twenty-four healthcare providers. Providers discussed several patient-level access barriers, such as not having health insurance, financial constraints, and scheduling difficulties. Providers believed socioeconomically disadvantaged patients were at-risk to misuse prescription opioids and were less comfortable prescribing opioids to these patients. This investigation found that providers perceived numerous patient-level barriers to pain care, expressed suspicion towards these patients, and considered patientsâ socioeconomic status when making pain management decisions. Future investigations should examine the extent to which providersâ attitudes influence their actual pain management decisions and lead to treatment disparities for this patient population
Impact of Race and Sex on Pain Management by Medical Trainees: A Mixed Methods Pilot Study of Decision Making and Awareness of Influence
Objective
Previous research suggests female and black patients receive less optimal treatment for their chronic pain compared with male and white patients. Provider-related factors are hypothesized to contribute to unequal treatment, but these factors have not been examined extensively. This mixed methods investigation examined the influence of patients' demographic characteristics on providers' treatment decisions and providers' awareness of these influences on their treatment decisions.
Methods
Twenty medical trainees made treatment decisions (opioid, antidepressant, physical therapy) for 16 virtual patients with chronic low back pain; patient sex and race were manipulated across patients. Participants then indicated from a provided list the factors that influenced their treatment decisions, including patient demographics. Finally, individual interviews were conducted to discuss the role of patient demographics on providers' clinical decisions.
Results
Individual regression analyses indicated that 30% of participants were reliably influenced by patient sex and 15% by patient race when making their decisions (Pâ<â0.05 or Pâ<â0.10). Group analyses indicated that white patients received higher antidepressant recommendations, on average, than black patients (Pâ<â0.05). Half of the medical trainees demonstrated awareness of the influence of demographic characteristics on their decision making. Participants, regardless of whether they were influenced by patients' demographics, discussed themes related to patient sex and race; however, participants' discussion of patient demographics in the interviews did not always align with their online study results.
Conclusions
These findings suggest there is a considerable variability in the extent to which medical trainees are influenced by patient demographics and their awareness of these decision making influences
Biopsychosocial correlates of persistent postsurgical pain in women with endometriosis
ObjectiveTo examine pain and biopsychosocial correlates over time for women with persistent postsurgical pain after surgery for endometriosis.MethodsCrossĂą sectional study of women who underwent any endometriosis surgery between 2003 and 2006. Following surgery, patients completed validated questionnaires (ShortĂą Form McGill Pain Questionnaire, 12Ăą item ShortĂą Form Health Survey, Beck Depression Inventory, Coping Strategies Questionnaire catastrophizing subscale). The primary outcome was pelvic pain intensity, measured by the McGill total pain score. Bivariate comparisons between each potential predictor and pain intensity were performed using the Ă 2 and t tests, 1Ăą way analysis of variance, and simple linear regression.ResultsIn total, 79 completed the questionnaires and were included in the present analysis. The McGill affective pain score was negatively correlated with age (ĂÂČĂą coefficient Ăą 0.12, P = 0.002) and positively correlated with catastrophization (ĂÂČĂą coefficient 0.66, P = 0.01). Women with a history of dyspareunia scored significantly higher on the McGill total pain score (P < 0.001); there was no association between pain intensity and endometriosis severity.ConclusionYounger age and catastrophization are correlated with persistent pain following surgery for endometriosis. The severity of endometriosis does not predict persistent pain. Further evaluation of psychosocial factors may identify patients who are least likely to benefit from surgeries for endometriosisĂą associated pelvic pain.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135478/1/ijgo169.pd
Balancing patient-centered and safe pain care for non-surgical inpatients: clinical and managerial perspectives
Background:
Hospitals and clinicians aim to deliver care that is safe. Simultaneously, they are ensuring that care is patient-centered, meaning that it is respectful of patientsâ values, preferences, and experiences. However, little is known about delivering care in cases where these goals may not align. For example, hospitals and clinicians are facing the daunting challenge of balancing safe and patient-centered pain care for nonsurgical patients, due to lack of comprehensive care guidelines and complexity of this patient population.
Methods:
To gather clinical and managerial perspectives on the importance, feasibility, and strategies used to balance patient-centered care (PCC) and safe pain care for nonsurgical inpatients, we conducted in-depth, semi-structured interviews with hospitalists (n=10), registered nurses (n=10), and health care managers (n=10) from one healthcare system in the Midwestern United States. We systematically examined transcribed interviews and identified major themes using a thematic analysis approach.
Results:
Participants acknowledged the importance of balancing PCC and safe pain care. They envisioned this balance as a continuum, with certain patients for whom it is easier (e.g., opioid-naĂŻve patient with a fracture), versus more difficult (e.g., patient with opioid use disorder). Participants also reported several strategies they use to balance PCC and safe pain care, including offering alternatives to opioids, setting realistic pain goals and expectations, and using a team approach.
Conclusions:
Clinicians and health care managers use various strategies to balance PCC and safe pain care for nonsurgical patients. Future studies should examine the effectiveness of these strategies on patient outcomes
Clinical perspectives on hospitalsâ role in the opioid epidemic
Policymakers, legislators, and clinicians have raised concerns that hospital-based clinicians may be incentivized to inappropriately prescribe and administer opioids when addressing pain care needs of their patients, thus potentially contributing to the ongoing opioid epidemic in the United States. Given the need to involve all healthcare settings, including hospitals, in joint efforts to curb the opioid epidemic, it is essential to understand if clinicians perceive hospitals as contributors to the problem. Therefore, we examined clinical perspectives on the role of hospitals in the opioid epidemic
Cultivating compliance: governance of North Indian organic basmati smallholders in a global value chain
Focusing on a global value chain (GVC) for organic basmati rice, we study how farmersâ practices are governed through product and process standards, organic certification protocols, and contracts with buyer firms. We analyze how farmersâ entry into the GVC reconfigures their agencements (defined as heterogeneous arrangements of human and nonhuman agencies which are associated with each other). These reconfigurations entail the severance of some associations among procedural and material elements of the agencements and the formation of new associations, in order to produce cultivation practices that are accurately described by the GVCâs standards and protocols. Based on ethnography of two farmers in Uttarakhand, North India, we find that the same standards were enacted differently on the two farmersâ fields, producing variable degrees of (selective) compliance with the âofficialâ GVC standards. We argue that the disjuncture between the âofficialâ scripts of the standards and actual cultivation practices must be nurtured to allow farmersâ agencements to align their practices with local sociotechnical relations and farm ecology. Furthermore, we find that compliance and disjuncture were facilitated by many practices and associations that were officially ungoverned by the GVC
An analytical approach for prediction of elastohydrodynamic friction with inlet shear heating and starvation
An analytical friction model is presented, predicting the coefficient of friction in elastohydrodynamic (EHD) contacts. Three fully formulated SAE 75W-90 axle lubricants are examined. The effect of inlet shear heating (ISH) and starvation is accounted for in the developed friction model. The film thickness and the predicted friction are compared with experimental measurements obtained through optical interferometry and use of a mini traction machine. The results indicate the significant contribution of ISH and starvation on both the film thickness and coefficient of friction. A strong interaction between those two phenomena is also demonstrated, along with their individual and combined contribution on the EHD friction
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