Search

The characteristics of traps between the Al0.25Ga0.75N barrier and the GaN channel layer in a high-electron-mobility-transistors (HEMTs) were investigated. The interface traps at the Al0.25Ga0.75N/GaN interface as well as the border traps were experimentally analyzed because the Al0.25Ga0.75N barrier layer functions as a dielectric owing to its high dielectric constant. The interface trap density Dit and border trap density Nbt were extracted from a long-channel field-effect transistor (FET), conventionally known as a FATFET structure, via frequency-dependent capacitance–voltage (C–V) and conductance–voltage (G–V) measurements. The minimum Dit value extracted by the conventional conductance method was 2.5 × 1012 cm−2·eV−1, which agreed well with the actual transistor subthreshold swing of around 142 mV·dec−1. The border trap density Nbt was also extracted from the frequency-dependent C–V characteristics using the distributed circuit model, and the extracted value was 1.5 × 1019 cm−3·eV−1. Low-frequency (1/f) noise measurement provided a clearer picture of the trapping–detrapping phenomena in the Al0.25Ga0.75N layer. The value of the border trap density extracted using the carrier-number-fluctuation (CNF) model was 1.3 × 1019 cm−3·eV−1, which is of a similar level to the extracted value from the distributed circuit model.

We presented an explicit empirical model of the thermal resistance of AlGaN/GaN high-electron-mobility transistors on three distinct substrates, including sapphire, SiC, and Si. This model considered both a linear and non-linear thermal resistance model of AlGaN/GaN HEMT, the thickness of the host substrate layers, and the gate length and width. The non-linear nature of channel temperature—visible at the high-power dissipation stage—along with linear dependency, was constructed within a single equation. Comparisons with the channel temperature measurement procedure (DC) and charge-control-based device modeling were performed to verify the model’s validity, and the results were in favorable agreement with the observed model data, with only a 1.5% error rate compared to the measurement data. An agile expression for the channel temperature is also important for designing power devices and monolithic microwave integrated circuits. The suggested approach provides several techniques for investigation that could otherwise be impractical or unattainable when utilizing time-consuming numerical simulations.

We sought to determine the impact of the indication for shunt placement on shunt-related outcomes after major arterial injuries. We hypothesized that a shunt placed for damage control indications would be associated with an increase in shunt-related complications including shunt dislodgement, thrombosis, or distal ischemia.A prospective, multicenter study (eleven level one US trauma centers) of all adult trauma patients undergoing temporary intravascular shunts (TIVS) after arterial injury was undertaken (January 2017-May 2019). Exclusion criteria included age15years, shunt placement distal to popliteal/brachial arteries, isolated venous shunts, and death before shunt removal. Clinical variables were compared by indication and shunt-related complications. The primary endpoint was TIVS complications (thrombosis, migration, distal ischemia).The 66 patients who underwent TIVS were primarily young (30years [IQR 22-36]) men (85%), severely injured (ISS 17 [10-25]) by penetrating mechanisms (59%), and had their shunts placed for damage control (41%). After a median SDT of 198min [89-622], 9% experienced shunt-related complications. Compared by shunt placement indication (damage control shunts [n=27] compared to non-damage control shunts [n=39]), there were no differences in gender, mechanism, extremity AIS, MESS score, fractures, or surgeon specialty between the two groups (all p0.05). Patients with shunts placed for damage control indications had more severe injuries (ISS 23.5 compared to 13; SBP 100 compared to 129; GCS 11 compared to 15; lactate 11.5 compared to 3.6; all p0.05), and had more frequent shunt complication predictors, but damage control shunts did not have significantly more TIVS complications (11.1% compared to 7.7%, p=0.658). Shunt complication patients were discharged home less often (33% vs 65%; p0.05) but all survived.Shunts placed for damage control indications were not associated with shunt complications in this prospective, multicenter study.

The objective of the present study was to assess muscle fibre composition by non-invasive methods for various sports events. 53 males of marathon (n=5), football (n=22), baseball (n=14), basketball (n=8) and tennis (n=4) athletes volunteered to participate in this study. The following 7 tests (overhead medicine ball throw, pull up, standing broad jump, sit up, shuttle run 10 x5, push up, vertical jump) are relatively easy to perform and to gather information about fibre composition through fitness levels. It can be used to assess the performance of strength using standard tables and to receive an indication of the degree of their share of fast (type II) and slow (type I) muscle fibres. For the study, a data analysis program in Microsoft Excel was used to view the mean and standard deviation of muscle fibre types. As a result, it was possible to speculate that the ratio of muscle fibre types differed according to the type of exercise. The results were obtained after sport motor tests of the mean value of muscle fibre composition by different sports events. Fibre type distribution remained with about 74.8% type 1 and 25.2% type 2 by marathoners, 43.8% type 1 and 53.2% type 2 by football athletes, 36.3% type 1 and 63.8% type 2 by baseball athletes, 46.6% type 1 and 53.5% type 2 by basketball athletes, and 40.0% type 1 and 60.0% type 2 by tennis athletes. Through these tests, the direction of the athletes’ muscle development can be considered, and it is possible to check the muscle fibre composition of elite athletes for the improvement of performance for each sport event. Moreover, it assumes that if this test is used for children, adolescents and young athletes, it will help to design scientific and effective training programs, thereby improving athletes’ ability to perform.

Background: Early diagnosis and prompt debridement of necrotizing soft tissue infection (NSTI) improves the outcome. We sought to determine whether failure to admit NSTI patients to acute care surg...

Background Outcome data on the very elderly patients undergoing emergency general surgery (EGS) are sparse. We sought to examine short- and long-term mortality in the 80 plus years population following EGS. Methods Using our institutional 2008-2018 EGS Database, all the 80 plus years patients undergoing EGS were identified. The data were linked to the Social Security Death Index to determine cumulative mortality rates up to 3 years after discharge. Univariate and multivariable logistic regression analyses were used to determine predictors of in-hospital and 1-year cumulative mortality. Results A total of 385 patients were included with a mean age of 84 years; 54% were female. The two most common comorbidities were hypertension (76.1%) and cardiovascular disease (40.5%). The most common procedures performed were colectomy (20.0%), small bowel resection (18.2%), and exploratory laparotomy for other procedures (15.3%; e.g., internal hernia, perforated peptic ulcer). The overall in-hospital mortality was 18.7%. Cumulative mortality rates at 1, 2, and 3 years after discharge were 34.3%, 40.5%, and 43.4%, respectively. The EGS procedure associated with the highest 1-year mortality was colectomy (49.4%). Although hypertension, renal failure, hypoalbuminemia, hyperbilirubinemia, and elevated liver enzymes predicted in-hospital mortality, the only independent predictors of cumulative 1-year mortality were hypoalbuminemia (odds ratio, 2.17; 95% confidence interval, 1.10-4.27; p = 0.025) and elevated serum glutamic pyruvic transaminase (SGOT) level (odds ratio, 2.56; 95% confidence interval, 1.09-4.70; p = 0.029) at initial presentation. Patients with both factors had a cumulative 1-year mortality rate of 75.0%. Conclusion More than half of the very elderly patients undergoing major EGS were still alive at 3 years postdischarge. The combination of hypoalbuminemia and elevated liver enzymes predicted the highest 1-year mortality. Such information can prove useful for patient and family counseling preoperatively. Level of evidence Prognostic, Level III.

Obese individuals are considered to have lower energy expenditure (EE) rates than non-obese individuals. We aimed to investigate the effects of various factors related to food intake on diet-induced thermogenesis (DIT) in the EE of obese individuals. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we reviewed relevant literature from PubMed, Embase, and Medline databases from study inception till the end of July 2019. Studies on dietary factors affecting DIT in obese individuals were included. Fifteen studies were included; these studies assessed macronutrient, single-nutrient, or supplement meal compositions, as well as dietary patterns and behaviors. The effect of obesity on DIT was not constant in each study. Differences in DIT pertained to the protein ratio being higher than the fat ratio or the carbohydrate ratio being higher than the fat ratio. High intake of calcium and vitamin D as well as high-oleic peanut supplements increased DIT in obese people. In addition, ascorbic acid intake, fatty acid saturation, and the chain length of various fatty acids had no effects on DIT. In conclusion, the findings suggest that in obese individuals, DIT is associated with various factors related to meal, nutrient, and dietary habits. However, because of the complexity of the relationship between DIT and obesity, it is difficult to determine the critical element underlying this association.

Research has demonstrated that older adults with multiple chronic diseases (CD) are particularly vulnerable to depression. Meeting current recommendations for physical activity (PA) may help ameliorate the impact of depression on this population. Nonetheless, the impact of frequency versus duration of PA on depression in older adults remains to be explored. Therefore, the purpose of the present study was to determine the combined effect of PA and multiple CD on depression and the combined effect of the frequency, duration, and multiple CD on depression in older adults. Methods: The present study utilized data from the 2017 and 2020 Living Profiles of Older People Surveys. Data from a total of 19,907 older adults (10,042 older adults from 2017 and 9865 older adults from 2020) were included in the present study. Depression was assessed using the Korean version of the Short Form of Geriatric Depression Scale (K-SGDS) and CD included cardiovascular disease, respiratory diseases, thyroid syndromes, orthopedic complications, and diabetes. Participants who participated in PA ≥ 150 min/week were categorized as the high PA group, and those who participated in PA < 150 min/week were categorized as the low PA group. Furthermore, the frequency of PA (FRE) was divided into high FRE (≥5 times/week) and low FRE (

The objective of this study was to describe and compare the timing of cervical spine clearance in trauma patients with an unreliable physical examination. We prospectively included adult trauma patients admitted with a cervical collar and an unreliable clinical examination (as defined by the NEXUS criteria) at two level 1 trauma centers: one in the USA (US) and one in Denmark (DK). We excluded patients with cervical spine injuries requiring a collar or surgery as treatment and patients with a collar placed after hospital arrival. The primary outcome was time from emergency department (ED) arrival to collar removal. Secondary outcomes included time to CT of the cervical spine (CTCS). At the US trauma center, an institutional protocol allowing cervical spine clearance exclusively by CTCS was in place. At the Danish trauma center, cervical spine clearance was based on a clinical evaluation by an orthopedic surgeon, usually after CTCS. A total of 113 patients were included (US: n = 56; DK: n = 57). The median age was 47 years, and 68% were males. The main reasons for an unreliable physical examination were a Glasgow Coma Scale score below 14 (35%), distracting injuries (26%), cervical spine tenderness (13%) and intoxication (13%). The injury severity score at the US trauma center was higher than at the DK trauma center (median: 17 vs. 11, p = 0.03). Both time to CTCS (median: 41 vs. 18 min, p

Background The long-term consequences of in-hospital complications remain largely unknown. We sought to study the effect of complications on the long-term functional outcome of trauma patients. Methods Patients with an Injury Severity Score ≥ 9 admitted to 3, level I trauma centers between 2015 and 2017 were contacted 6 to 12 months postinjury and administered a validated trauma quality-of-life survey, assessing for the presence of any functional limitation. Functional limitation was defined as the inability to perform independently one or more activities of daily living (eg, driving, walking on flat surfaces/upstairs, dressing). Medical records and the trauma registry were reviewed systematically for all patient and injury variables. The occurrence of predefined in-hospital complications (eg, pneumonia, surgical site infection) was recorded. The impact of in-hospital complications on functional limitation was assessed using multivariate logistic regression models. Results Of 1,709 patients, 1,022 completed the study. The mean age was 58 y, 56% were male, 94% had blunt trauma, and the mean Injury Severity Score was 15. A total of 168 patients (16.4%) had a minimum of 1 in-hospital complication and reported significantly more functional limitations in most activities of daily living at 6 to 12 months, compared with those without complications. In multivariable analyses adjusting for confounders, the occurrence of complications was associated with a greater likelihood of functional limitation 6 to 12 months postinjury (odds ratio = 1.82, 95% confidence interval 1.22–2.69, P = .003). Conclusion Trauma patients with in-hospital complications have a worse long-term functional outcome. In addition to prevention of primary complications, more rehabilitation resources should be made available to trauma patients who survive complications.

Background Recent small randomized trials suggest that primary anastomosis with a diverting loop ileostomy (PADLI) is a safe alternative to Hartmann's procedure (HP) for patients with acute diverticulitis necessitating emergent operation. We sought to examine the 30-day outcomes of patients undergoing emergent HP vs PADLI. Method Using the American College of Surgeons NSQIP Colectomy Procedure Targeted Database from 2012 to 2016, all patients with acute diverticulitis who underwent emergent HP or PADLI were identified. Multivariable logistic models were constructed to compare the 30-day mortality, overall morbidity, and individual postoperative complications (eg surgical site infection, bleeding, sepsis) of the 2 procedures, controlling for all preoperative variables (eg demographics, comorbidities, laboratory values, illness severity), as well as intraoperative and procedure-specific variables (eg wound classification). Results Of 130,963 patients, 2,729 patients were included. Median age was 64 years, 48.5% were male; the majority of patients underwent HP and only 208 (7.6%) underwent PADLI. Hartmann's procedure patients had more comorbidities (eg COPD: 9.8% vs 4.8%; p = 0.017), were more functionally dependent (6.3% vs 2.4%; p = 0.025), and were sicker (eg septic shock: 11.1% vs 5.3%; p = 0.015) compared with PADLI patients. The mortality rates for HP vs PADLI were 7.6% and 2.9%, respectively (p = 0.011). The morbidity rates were 55.4% and 48.6%, respectively (p = 0.056). In multivariable analyses, compared with HP, PADLI did not result in increased rates of mortality (odds ratio 0.21; 95% CI 0.03 to 1.58; p = 0.129) or morbidity (odds ratio 0.96; 95% CI 0.63 to 1.45; p = 0.834). The odds of most major postoperative complications were also similar for HP and PADLI overall. Conclusions Currently, surgeons perform HP more frequently than PADLI. When controlling for patient population differences, PADLI appears to be at least a safe alternative to HP for select patient populations needing emergent surgical management of acute diverticulitis.