Control of electron energy distributions and plasma characteristics of dual frequency, pulsed capacitively coupled plasmas sustained in Ar and Ar/CF 4 /O 2

The fluxes of radicals and ions to the wafer during plasma processing of microelectronics devices determine the quality of the etch or deposition. These fluxes are largely controlled by controlling the electron energy distribution function f ( ε ) which determines the dissociation patterns of feedstock gases. In quasi-steady state operation, an equilibrium condition for f ( ε ) results from a real time balance between electron sources and sinks. Using pulsed power, electron sources and sinks do not need to instantaneously balance—they only need to balance over the longer pulse period. This provides additional leverage to customize f ( ε ). In this paper, the f ( ε ) in a two-frequency, pulsed capacitively coupled plasma sustained in Ar and Ar/CF 4 /O 2 mixtures are discussed with results from a two-dimensional plasma hydrodynamics model. The f ( ε ) are obtained from a Monte Carlo simulation which includes electron–electron collisions. We found that the f ( ε ) and rate coefficients can be controlled by pulse repetition frequency (PRF) and duty cycle (DC) of the pulsed power in a manner not otherwise easily attainable using continuous excitation. The tail of the f ( ε ) is enhanced with smaller PRF and DC in order to compensate for the electron losses during the power-off portion of the cycle.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98613/1/0963-0252_21_5_055028.pd

Control of Plasma Kinetics for Microelectronics Fabrication.

The fluxes of radicals and ions to the wafer during plasma processing of microelectronics devices determine the quality of the etch or deposition. These fluxes are largely controlled by controlling the electron energy distribution (EED) which determines the dissociation patterns of feedstock gases. Also, the quality of the process is in large part determined by the ability to control the ion energy distribution (IED) onto the wafer. In this thesis, the possibilities of controlling EED and IED are modeled using a two-dimensional plasma equipment model. The techniques to control the EED include a magnetic field, beam electrons and a pulsed power source. Due to the magnetic confinement, the EED varies with position of the chamber depending on the pressure and power. Using beam electrons also provides a possibility to customize EED by delivering the energy to the bulk electrons through the e-e collisions. In dual frequency capacitively coupled plasmas (DF-CCP), the pulsed power is one technique being investigated to provide additional degrees of freedom to control the EED and IED. By using pulsed power, electron sources and sinks do not need to instantaneously balance – they only need to balance over the longer pulse period. This provides additional leverage to customize EED and IED. As an application, the etching properties were also investigated in the DF-CCP using pulsed power. In the pulsed operation, there are typically two phases; deposition and etching. As a result, using pulse power provides one with the ability to control the balance between the etching and deposition, which enables us to manipulate the etching profile. It was found that sidewall bowing can be suppressed by pulsing.PHDNuclear Engineering & Radiological SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/108809/1/ssongs_1.pd

Automatic segmentation of wrist bone fracture area by K-means pixel clustering from X-ray image

Early detection of subtle fracture is important particularly for the senior citizens’ quality of life. Naked eye examination from X-ray image may cause false negatives due to operator subjectivity thus computer vision based automatic detection software is much needed in practice.  In this paper, we propose an automatic extraction method for suspisious wrist fracture regions. We apply K-means in pixel clustering to form the candidate part of possible fracture from wrist X-ray image automatically. This method can recover previously detected patterned false cases with edge detection method after fuzzy stretching. The proposed method is successful in 16 out of 20 tested cases in experiment

New Tubulocentric Insights for Diabetic Nephropathy: From Pathophysiology to Treatment

The prevalence of diabetes is increasing worldwide, and one of the most important complications, diabetic nephropathy, constitutes a significant global health care and socioeconomic burden. Glomerular dysfunction is a major factor in the development and progression of diabetic nephropathy. However, emerging evidence suggests that tubular damage also plays an important role in the pathogenesis of diabetic nephropathy. This tubulocentric view shifts the focus markedly from glomeruli to proximal tubules, which might have an important role as a trigger or a driver in the early development and progression of diabetic nephropathy. Accordingly, numerous studies have focused on several different tubular damage markers that are clinically indicated as potential biomarkers for the early detection of diabetic nephropathy. Furthermore, these findings are relevant for identifying therapeutics for diabetic nephropathy that target the proximal tubules. This review outlines new tubulocentric insights into diabetic nephropathy, from pathophysiological mechanisms to diagnostic and therapeutic approaches

Subpleural Pulmonary Hyalinizing Granuloma Presenting as a Solitary Pulmonary Nodule

AbstractWe introduce a case of pulmonary hyalinizing granuloma presented as a solitary pulmonary nodule located subpleurally. The patient was a 57-year-old man who had abnormal chest roentgenograms showing a solitary pulmonary nodule in the right lower lung field. The nodule was resected for definitive diagnosis and histopathologically proved to be pulmonary hyalinizing granuloma. In previously reported cases, most patients had ill-defined margins and usually bilateral, multiple lesions radiographically. In our case, the subpleural location is an uncommon location of this rare entity

Intraoperative blood loss during different stages of scoliosis surgery: A prospective study

<p>Abstract</p> <p>Background</p> <p>There are a number of reasons for intraoperative blood loss during scoliosis surgery based on the type of approach, type of disease, osteopenia, and patient blood profile. However, no studies have investigated bleeding patterns according to the stage of the operation. The objective of this prospective study was to identify intraoperative bleeding patterns in different stages of scoliosis surgery.</p> <p>Methods</p> <p>We prospectively analyzed the estimated blood loss (EBL) and operation time over four stages of scoliosis surgery in 44 patients. The patients were divided into three groups: adolescent idiopathic (group 1), spastic neuromuscular (group 2) and paralytic neuromuscular (group 3). The per-level EBL and operation times of the groups were compared on a stage-by-stage basis. The bone marrow density (BMD) of each patient was also obtained, and the relationship between per-level EBL and BMD was compared using regression analysis.</p> <p>Results</p> <p>Per-level operation time was similar across all groups during surgical stage (p > 0.05). Per-level EBL was also similar during the dissection and bone-grafting states (p > 0.05). However, during the screw insertion stage, the per-level EBL was significantly higher in groups 2 and 3 compared to group 1 (p < 0.05). In the correction stage, per-level EBL was highest in group 3 (followed in order by groups 2 and 1) (p < 0.05). Preoperative BMD indicated that group 3 had the lowest bone quality, followed by groups 2 and 1 (in order), but the preoperative blood indices were similar in all groups. The differences in bleeding patterns in the screw insertion and correction stages were attributed to the poor bone quality of groups 2 and 3. Group 3 had the lowest bone quality, which caused loosening of the bone-screw interface during the correction stage and led to more bleeding. Patients with a T-score less than -2.5 showed a risk for high per-level EBL that was nine times higher than those with scores greater than -2.5 (p = 0.003).</p> <p>Conclusions</p> <p>We investigated the blood loss patterns during different stages of scoliosis surgery. Patients with poor BMD showed a risk of blood loss nine times higher than those with good BMD.</p

Clinical features and outcomes of elderly patients with antineutrophil cytoplasmic antibody-positive vasculitis: a single-center retrospective study

Background We aimed to investigate the clinical characteristics and outcomes of patients aged ≥65 years with antineutrophil cytoplasmic autoantibody (ANCA)-positive ANCA-associated vasculitis (AAV) in Korea. Methods Seventy patients diagnosed with ANCA-positive AAV from 2006 to 2019 at a single center were analyzed and categorized into younger (aged <65 years) or elderly (aged ≥65 years) groups. Initial induction treatments were investigated according to age group. All-cause mortality and kidney outcomes were evaluated. Results After categorization by age, 34 (48.6%) and 36 patients (51.4%) were in the younger and elderly groups, respectively. In the elderly group, more patients were treated with oral cyclophosphamide (CYC) (30.6%) than with intravenous CYC (19.4%). During a median follow-up of 14.6 months (range, 3.0–53.1 months), 13 patients died (elderly group: 11 patients, 84.6%). In the elderly group, older age (hazard ratio [HR], 1.44; 95% confidence interval [CI], 1.09–1.90; p = 0.01), lower hemoglobin (HR, 0.21; 95% CI, 0.08–0.60; p = 0.003), and higher serum creatinine level (HR 14.17; 95% CI, 1.29–155.84; p = 0.03) were significant risk factors for all-cause mortality after adjustment. Oral CYC + steroid treatment was associated with decreased all-cause mortality compared to untreated induction immunosuppressants (HR, 0.01; 95% CI, 0.001–0.47; p = 0.02). Kidney failure or kidney recovery outcomes were not significantly different between the younger and elderly groups. Conclusion Patients aged ≥65 years had higher mortality rates than younger patients, and mortality was associated with older age, lower hemoglobin, higher serum creatinine level, and nontreatment compared to oral CYC + steroids

Effects of 12 weeks nutrition education on nutritional status in hemodialysis patients

Protein-energy malnutrition is present in a large proportion of patients with end stage renal disease and, is a strong risk factor for mortality in these patients. This study was aimed to evaluate the effectiveness of 12-weeks nutrition education during the hemodialysis session for the improvement of nutritional status. From the June 2011 to the September 2011, patients who were on regular hemodialysis in Pusan National University Hospital were enrolled in this study. In education group, intensive nutrition education was performed by the hemodialysis nurse, for fifty to sixty minutes during the hemodialysis session, once a week. Curriculum for renal nutrition includes regular taking of their medication, intake of moderate amount of protein and sufficient calories, reduction of water, salt, potassium and phosphate intake. Otherwise, any education program was not performed in patients of control group. Nutrition status was assessed by the subjective global assessment (SGA),body mass index (BMI), triceps skinfold thickness (TSF), arm muscle area(AMC) and laboratory markers such as serum albumin, serum blood urea nitrogen(BUN) and hemoglobin(Hb) level before and after the education. Effect of nutrition education was analyzed using ANCOVA test. A total of 49 patients were enrolled in this study and nutrition education was provided to 25 hemodialysis patients. Their mean age was 57.20±15.49 in education group and 55.13±14.42 in control groupand male was 56.0% in education group and 50.0% in control group and, other baseline characteristics were not significantly different between two groups. After the 12-week education, significant improvement was found in SGA, serum albumin, BUN and Hb level. SGA score was improved from 6.36±0.99 to 6.72±0.61 in education group, compared to control group(6.38±0.88 to 6.42±0.88, p=0.029 ). Improvement of serum albumin level, BUN and Hb was as follows: serum albumin(4.23±0.28 to 4.30±0.25 in education group, 4.28±0.39 to 4.13±0.34 in control group, p=0.040), serum Hb(10.45±1.49 to 11.13±1.74 in education group, 10.51±1.12 to 10.04±1.02 in control group, P=0.004), serum BUN(66.52±18.76 to 70.94±17.26 in education group, 59.50±13.61 to 58.68±13.88 in control group, p=0.032). 12 week nutrition education during the hemodialysis session by hemodialysis nurse was effectiv