Least-cost decarbonization pathways for electricity generation in Finland: A convex quantile regression approach.

This study investigates the least-cost decarbonization pathways in the Finnish electricity generation industry in order to achieve the national carbon neutrality goal by 2035. Various abatement measures, such as downscaling production, capital investment, and increasing labor and intermediate inputs, are considered. The marginal abatement costs (MACs) of greenhouse gas emissions are estimated using the convex quantile regression method and applied to unique register-based firm-level greenhouse gas emission data merged with financial statement data. We adjust the MAC estimates for the sample selection bias caused by zero-emission firms by applying the two-stage Heckman correction. Our empirical findings reveal that the median MAC ranges from 0.1 to 3.5 euros per tonne of CO2 equivalent. The projected economic cost of a 90% reduction in emissions is 62 million euros, while the estimated cost of achieving zero emissions is 83 million euros.

Phase transition of DNA knotting in spherical space.

Knots have been discovered in various biological systems, such as DNA. The knotting probability of DNA in free space depends non-monotonically on its bending rigidity and has a prominent peak. The current work aims to understand the underlying mechanism of the non-monotonic dependence of DNA knotting probability on bending rigidity. Monte Carlo simulations are performed on a closed DNA molecule confined in spherical space described by a worm-like chain model and a flexible kink model, respectively. The closed DNA's contour length and the spherical space radius both increase knotting probability, but also alter the unimodal dependence of knotting probability on bending rigidity. This is generalized using universal phase diagrams based on the two models. Under the flexible kink model, the total knotting probability of closed DNA is obviously increased at a relatively high excited energy. This supports the expectation that the entropy effect of knot size favours knot formation at a relatively low bending rigidity. In a given spherical space, the increasing contour length of closed DNA described by the worm-like chain model results in a visible shift in the knotting probability distribution. At the same time, the gyration radius of non-trivial closed DNA becomes comparable to that of trivial closed DNA, so that their ratio is not anti-correlated with average knot length. For closed DNA of various contour lengths, the relationship between average knot length and bending rigidity has a universal behaviour: the average knot length decreases to a local minimum at a bending rigidity of ∼5 and then gradually increases to a constant value. The existence of the local minimum is determined by the cut-off distance in repulsive Lennard-Jones potential. The bending rigidity corresponding to the beginning of the constant average knot length is consistent with that at the peak in the knotting distribution. At this point, the knot-size effect balances with the fragment free-energy effect and, at an even greater bending rigidity, knot length breathes around the average knot length value.

Clinical outcomes, quality of life, and costs evaluation of peritoneal dialysis management models in Shanghai Songjiang District: a multi-center and prospective cohort study.

Background: The new Family-Community-Hospital (FCH) three-level comprehensive management aimed to improve the efficiency and scale of peritoneal dialysis (PD) to meet the increased population of end-stage renal disease (ESRD). Our study focused on the clinical outcomes, quality of life, and costs evaluation of this model in a multi-center and prospective cohort study.Methods: A total of 190 ESRD patients who commenced PD at Shanghai Songjiang District were enrolled. According to different PD management models, patients were divided into the Family-Community-Hospital three-level management model (n = 90) and the conventional all-course central hospital management model (n = 100). The primary outcome was clinical outcomes of PD. The secondary outcomes were health-related quality of life (HRQOL) and medical costs evaluation.Results: Compared to conventional management, community-based FCH management achieved a similar dialysis therapeutic effect, including dropout rate (p = 0.366), peritonitis rate (p = 0.965), patient survival (p = 0.441), and technique survival (p = 0.589). Follow-up data showed that similar levels of the renal and peritoneal functions, serum albumin, cholesterol and triglyceride, PTH, serum calcium, and phosphorus between the two groups (all p > 0.05). HRQOL survey showed that the FCH management model helped to improve the psychological status of PD patients, including social functioning (p = 0.006), role-emotional (p = 0.032), and mental health (p = 0.036). FCH management also reduced the hospitalization (p = 0.009) and outpatient visits (p = 0.001) and saved annual hospitalization costs (p = 0.005), outpatient costs (p = 0.026), and transport costs (p = 0.006).Conclusions: Compared with conventional management, community-based FCH management achieved similar outcomes, improved psychological health, reduced medical budgets, and thus had a good social prospect.

Persistent Racial and Sex Disparities in Outcomes After Coronary Artery Bypass Surgery: A Retrospective Clinical Registry Review in the Drug-eluting Stent Era.

OBJECTIVE: The purpose of this study was to assess the temporal trends in 30-day mortality by race group for patients undergoing coronary artery bypass grafting (CABG) between 2011 and 2018 and to investigate the effect of race and sex on postoperative outcomes after CABG. SUMMARY BACKGROUND DATA: Cardiovascular diseases remain a leading cause of death in the United States with studies demonstrating increased morbidity and mortality for black and female patients undergoing surgery. In the post drug-eluting stent era, studies of racial disparities CABG are outdated. METHODS: We performed a retrospective analysis of the Society for Thoracic Surgeons database for patients undergoing CABG between 2011 and 2018. Primary outcome was 30-day mortality. Secondary outcomes included postoperative length of stay, surgical site infection, sepsis, pneumonia, stroke, reoperation, reintervention, early extubation, and readmission. RESULTS: The study population was comprised of 1,042,506 patients who underwent isolated CABG between 2011 and 2018. Among all races, Black patients had higher rates of preoperative comorbidities. Compared with White patients, Black patients had higher overall mortality (2.76% vs 2.19%, P < 0.001). On univariable regression, Black patients had higher rates of death, infection, pneumonia, and postoperative stroke compared to White patients. On multivariable regression, Black patients had higher odds of 30-day mortality compared to white patients [odds ratio (OR) = 1.11, 95% confidence interval (CI) 1.05-1.18]. Similarly, female patients had higher odds of death compared to males (OR = 1.26, 95% CI 1.21-1.30). CONCLUSIONS: In the modern era, racial and sex disparities in mortality and postoperative morbidity after coronary bypass surgery persist with Black patients and female patients consistently experiencing worse outcomes than White male patients. Although there may be unknown or underappreciated biological mechanisms at play, future research should focus on socioeconomic, cultural, and multilevel factors.

Macromolecule crowding effects on the phase separation of semi-flexible polymer in spherical confined space.

Current works focus on detecting macromolecule crowding effects on the phase separation of the mixture between semi-flexible polymer and crowders (hydrophilic polymers) in confined space by Monte Carlo simulations. With the increasing addition of crowders into the spherical confined space, the semi-flexible polymer was first compressed into a condensed state from the initial coil state, and then the condensed conformation expanded and deposited on the inner surface of the spherical confined space with an extended state. The phase diagram in the phase space of the volume fraction of crowders and the scaled radius of spherical confined space by crowder diameter, and the direct conformation transition of semi-flexible polymer have validated the phase transition process successfully. In addition, the deposition of extended conformation on the inner surface of the spherical confined space was qualified by the vertex density, its curve shifted along the radial direction with the increasing volume fraction of crowder. During the phase separation process, the critical volume fraction φ∗ relates to the crowder diameter approximately linearly and the relation between the critical volume fraction and the crowder diameter strongly depends on the size of the spherical confined space.

Discrepancies in access and institutional risk tolerance in heart transplantation: A national open cohort study.

BACKGROUND: The impact of center volume on heart transplantation is widely recognized and serves as a benchmark for certification and reimbursement. STUDY AIMS: Study sociodemographic variables associated with access to high-volume centers and substantiate the importance of extending access to underserved populations. METHODS: This study focused on adults undergoing heart transplantation between 2006 and 2015. Centers were clustered into terciles (>25, 14-25, or <14 transplants per year) and factors associated with receiving care in different terciles were identified through multinomial regression. RESULTS: During the study period, 18 725 patients were transplanted at 145 centers. Younger age (<30 years) (P = .005), lower educational level (P < .001), and government-based insurance (P < .001) were associated to lower odds of receiving care at a high-volume center. These centers had higher risk recipients and accepted organs from higher risk donors, when compared to intermediate- and low-volume centers. Receiving care at high (odds ratio [OR], 1.212; P = .017) and intermediate-volume centers (OR, 1.304; P = .001) was associated with greater odds of 1-year survival when compared with low-volume centers. CONCLUSION: Social, demographic, and geographic factors affect access to high- and intermediate-volume centers. High-volume centers tolerate more risk while providing excellent survival. Awareness of this impact should prompt an extension of access to care for underserved patient populations.

Children's Heart Assessment Tool for Transplantation (CHAT) Score: A Novel Risk Score Predicts Survival After Pediatric Heart Transplantation.

BACKGROUND: Given the shortage of donor organs in pediatric heart transplantation (HTx), pretransplant risk stratification may assist in organ allocation and recipient optimization. We sought to construct a scoring system to preoperatively stratify a patient's risk of one-year mortality after HTx. METHODS: The United Network for Organ Sharing database was queried for pediatric (<18 years) patients undergoing HTx between 2000 and 2016. The population was randomly divided in a 4:1 fashion into derivation and validation cohorts. A multivariable logistic regression model for one-year mortality was constructed within the derivation cohort. Points were then assigned to independent predictors ( P < .05) based on relative odds ratios (ORs). Risk groups were established based on easily applicable, whole-integer score cutoffs. RESULTS: A total of 5,700 patients underwent HTx; one-year mortality was 10.7%. There was a similar distribution of variables between derivation (n = 4,560) and validation (n = 1,140) cohorts. Of the 12 covariates included in the final model, nine were allotted point values. The low-risk (score 0-9), intermediate-risk (10-20), and high-risk (>20) groups had a 5.18%, 10%, and 28% risk of one-year mortality ( P < .001), respectively. Both intermediate-risk (OR = 2.46, 95% confidence interval [95% CI]: 1.93-3.15; P < .001) and high-risk (OR = 9.24, 95% CI: 6.92-12.35; P < .001) scores were associated with an increased risk of one-year mortality when compared to the low-risk group. CONCLUSIONS: The Children's Heart Assessment Tool for Transplantation score represents a pediatric-specific, recipient-based system to predict one-year mortality after HTx. Its use could assist providers in identification of patients at highest risk of poor outcomes and may aid in pretransplant optimization of these children.

Racial Disparities in Patients Bridged to Heart Transplantation With Left Ventricular Assist Devices.

BACKGROUND: Left ventricular assist devices (LVADs) are an effective therapy in bridging patients with end-stage heart failure to heart transplantation. The aim of this study was to identify the role of race in survival of patients bridged to heart transplantation with a LVAD. METHODS: The United Network of Organ Sharing database was queried for all adult heart transplant recipients (age 18 years or older) who were bridged to transplantation with a LVAD from 2005 to 2018. Patients were stratified based on their race, with whites as the reference group. Demographic characteristics, 5-year survival, and graft failure after transplantation were assessed with χ2 test, analysis of variance, Kaplan-Meier survival analyses, log-rank tests, and Cox proportional hazards modeling or logistic regression modeling as appropriate. RESULTS: Patients (N = 6476) successfully bridged with a LVAD to heart transplantation were identified. There were 4263 whites, 1536 African Americans, 508 Hispanics, and 169 Asians. Compared with whites, African Americans had higher body mass indexes, were more likely to be women, pay with private insurance, and be working for income at the time of transplantation. African Americans were found to have increased odds of graft failure (odds ratio 1.27, P = .048) compared with whites. In addition, African Americans were found to have increased risk of mortality at 5 years (hazard ratio 1.26, P = .003). CONCLUSIONS: The African American race is associated with increased rates of graft failure after transplantation and decreased 5-year survival compared with the white race. Given these findings, directed clinical attention may be warranted in African American patients bridged to heart transplantation with a LVAD.

Non-invasive dynamic assessment of conjunctival melanomas by photoacoustic imaging.

This study describes non-invasive photoacoustic imaging to detect and monitor the growth of conjunctival melanomas in vivo. Conjunctival melanomas were induced by injection of melanotic B16F10 cells into the subconjunctival space in syngeneic albino C57BL/6 mice. Non-invasive in vivo photoacoustic tomography was performed before, and after tumor induction up to 2 weeks. Spectral unmixing was performed to determine the location and to assess the distribution of melanin. The melanin photoacoustic signal intensity was quantified from the tumor-bearing and control eyes at all timepoints. For postmortem validation, total tumor and melanotic tumor volumes were measured using H&E stained tumor sections and were compared to in vivo photoacoustic imaging measurements. Photoacoustic imaging non-invasively detected eyes bearing conjunctival tumors of varying sizes. The melanin signal was detected as early as immediately following injection of melanotic tumor cells. Changes in tumor size over time were assessed with changes in the volume and intensity of the melanin signal. Four growing tumors and one regressing tumor were observed. Three tumors without significant change in signal intensity over time were observed, showing variable growth. Photoacoustic melanin signal on the last day of in vivo imaging correlated with postmortem total tumor volume (R2 = 0.81) and melanotic tumor volume (R2 = 0.80). The results of our study show that actively growing conjunctival melanomas can be quantified in a non-invasive manner using in vivo photoacoustic tomography. The photoacoustic melanin signal intensity correlated with total and melanotic tumor volume. This novel in vivo imaging platform may help to assess new treatment modalities to manage ocular tumors.

The impacts of surface ozone pollution on winter wheat productivity in China--An econometric approach.

The impact of surface ozone pollution on winter wheat yield is empirically estimated by considering socio-economic and weather determinants. This research is the first to use an economic framework to estimate the ozone impact, and a unique county-level panel is employed to examine the impact of the increasing surface ozone concentration on the productivity of winter wheat in China. In general, the increment of surface ozone concentration during the ozone-sensitive period of winter wheat is determined to be harmful to its yield, and a conservative reduction of ozone pollution could significantly increase China's wheat supply.

Is Medical Student Interest in Cardiothoracic Surgery Maintained After Receiving Scholarship Awards?

BACKGROUND: Medical student exposure to cardiothoracic surgery has been facilitated by many scholarship opportunities. This study reviews the long-term interest of students at our institution who have received such support. METHODS: After the first or second year of medical school, participants were selected to receive scholarships for clinical or research activities in cardiothoracic surgery ranging from 4 to 8 weeks in duration. These were funded by the American Association for Thoracic Surgery, Society of Thoracic Surgeons, Southern Thoracic Surgical Association, or a private family donor. Over time, each student's scholarship type, current interest in cardiothoracic surgery, and current education or career status was prospectively monitored in an institutional database. RESULTS: Since 1999, 45 students received scholarships. Eight (18%) were funded by the American Association for Thoracic Surgery, two (4%) by The Society of Thoracic Surgeons one (2%) by the Southern Thoracic Surgical Association, and 34 (76%) by private donors. The median follow-up of graduated students is 7 years. Of the 20 (44%) with an active current interest in cardiothoracic surgery, 2 are faculty, 1 is a fellow, 1 is in an integrated 6-year program, 11 are in general surgery residency and are planning to apply to cardiothoracic surgery fellowship, and the remaining 5 are in medical school and planning a cardiothoracic surgery career. Of all former medical students who received cardiothoracic surgery research scholarships and who have now made a career choice, 17.4% chose cardiothoracic surgery. CONCLUSIONS: More than one-third of medical students who received scholarships in cardiothoracic surgery maintained their interest over time, and more than half maintained interest in a surgical field. Although long-term data are scarce, it remains critical to foster mentoring relationships with students over time to guide their career choices.