Data from 2016 show ongoing positive trends in short-and long-term allograft survival, and a decrease in the number of active listed candidates for the first time in more than a decade, with a concomitant increase in deceased donor kidney transplants. Transplant rates that had changed dramatically for some groups after implementation of the new kidney allocation system in 2014 are stabilizing, allowing for evaluation of new steady states and trends. Many challenges remain in adult kidney transplantation, including stagnant rates of living donor transplant, geographic disparities in access to transplant, racial disparities in living donor transplant, and overall a continuing demand for kidneys that far outpaces the supply. For pediatric recipients, a decline in the proportion of living donor transplants is of concern. In 2016, only 34.2% of pediatric transplants were from living donors, compared with 47.2% in 2005. The number of related donors decreased dramatically over the past decade, and the number of unrelated directed transplants performed in pediatric candidates remained low (50).

Despite the ongoing severe shortage of available kidney grafts relative to candidates in need, data from 2019 reveal some promising trends. After remaining relatively stagnant for many years, the number of kidney transplants has increased each year since 2015, reaching the highest annual count to date of 24,273 in 2019. The number of patients waiting for a kidney transplant in the United States was relatively stable, despite an increase in the number of new candidates added in 2019 and a decrease in patients removed from the waiting list owing to death or deteriorating medical condition. However, these encouraging trends are tempered by ongoing challenges. Nationwide, only a quarter of waitlisted patients receive a deceased‐donor kidney transplant within 5 years, and this proportion varies dramatically by donation service area, from 15.5% to 67.8%. The non‐utilization (discard) rate of recovered organs remains at 20.1%, despite adramatic decline in the discard of organs from hepatitis C‐positive donors. Non‐utilization rates remain particularly high for Kidney Donor Profile Index ≥85% kidneys and kidneys from which a biopsy specimen was obtained. While the number of living‐donor transplants increased again in 2019, only a small proportion of the waiting list receives living‐donor transplants each year, and racial disparities in living‐donor transplant access persist. As both graft and patient survival continue to improve incrementally, the total number of living kidney transplant recipients with a functioning graft is anticipated to exceed 250,000 in the next 1‐2 years. Over the past decade, the total number of pediatric kidney transplants performed has remained stable. Despite numerous efforts, living donor kidney transplant remains low among pediatric recipients with continued racial disparities among recipients. Congenital anomalies of the kidney and urinary tract remain the leading cause of kidney disease. While most deceased donor recipients receive a kidney from a donor with KDPI less than 35%, the majority of pediatric recipients had four or more HLA mismatches. Graft survival continues to improve with superior outcomes for living donor recipients.

Data on adult liver transplants performed in the US in 2017 are notable for (1) continued growth in numbers of new waitlist registrants (11,514) and of transplants performed (8,082); (2) continued increase in the transplant rate (51.5 per 100 waitlist-years); (3) a precipitous decrease in waitlist registrations and transplants for hepatitis C-related indications; (4) reciprocal increases in waitlist registrants and recipients with alcoholic liver disease and with clinical profiles consistent with non-alcoholic fatty liver disease; and (5) continued improvement in graft survival despite changing recipient characteristics such as older age and higher rates of obesity. Variability in transplant rates remained by candidate race, presence of hepatocellular carcinoma, urgency status (status 1A versus model for end-stage liver disease (MELD) score >35), and geography. More than half

Many positive trends in kidney transplantation were notable in 2017. Deceased donor kidney transplant rates and counts continued to rise, the kidney transplant waiting list declined for the third year in a row after decades of growth, and both short-and long-term allograft survival continued to improve year over year. In total, more than 220,000 patients were living in the United States with a functioning allograft. With 3 years of data available since implementation of the new kidney allocation system, better prediction of longer-term results of the allocation policy changes became possible. The data also reveal several areas in need of improvement and attention. Overall, the challenge of providing adequate access to kidney transplant persisted nationally, with additional dramatic regional variation. The proportion of living donor kidney transplants in both adults and children continued to fall, and racial disparities in living donor kidney transplant grew in the past decade. Patients at start of year 99,322 98,018 95,658 Patients added during year 30,215 30,854 30,918 Patients removed during year 31,466 33,167 33,891 Patients at end of year 98,071 95,706 92,685

We describe in detail a set of ideas for implementing qubits, quantum gates and quantum gate networks in a semiconductor heterostructure device. Our proposal is based on an extension of the technology used for surface acoustic wave (SAW) based single-electron transport devices. These devices allow single electrons to be captured from a two-dimensional electron gas in the potential minima of a SAW. We discuss how this technology can be adapted to allow the capture of electrons in pure spin states and how both single and two-qubit gates can be constructed using magnetic and non-magnetic gate technology. We give designs for readout gates to allow the spin state of the electrons to be measured and discuss how combinations of gates can be connected to make multi-qubit networks. Finally we consider decoherence and other sources of error, and how they can be minimized for our design

In 2016, 3209 heart transplants were performed in the United States. New, active listings increased 57% since 2005. The number of adult heart transplant survivors continued to increase, and in 2016, 30,622 recipients were living with heart transplants. Patient mortality following transplant has declined. The number of pediatric candidates and transplants performed also increased. New listings for pediatric heart transplants increased from 454 in 2005 to 624 in 2016. The number of pediatric heart transplants performed each year increased from 319 in 2005 to 445 in 2016. Among pediatric patients who underwent transplant in 2015, death occurred in 5.9% at 6 months and 7.2% at 1 year.

In 2017, 3273 heart transplants were performed in the United States. New listings continued to increase, and 3769 new adults were listed for heart transplant in 2017. Over the past decade, posttransplant mortality has declined. The number of new pediatric listings increased over the past decade, as did the number of pediatric heart transplants, although some fluctuation has occurred more recently. New listings for pediatric heart transplants increased from 481 in 2007 to 623 in 2017. The number of pediatric heart transplants performed each year increased from 330 in 2007 to 432 in 2017, slightly fewer than in 2016. Short-term and long-term mortality improved. Among pediatric patients who underwent transplant between 2015-2016, 4.8% had died by 6 months and 6.2% by 1 year.

In 2016, 2692 candidates aged 12 years or older were added to the lung transplant waiting list; 2345 transplants were performed, the largest number of any prior year. The median waiting time for listed candidates in 2016 was 2.5 months, and waiting times were shortest for group D candidates. The transplant rate increased to 191.9 transplants per 100 waitlist years in 2016, with a slight decrease in waitlist mortality to 15.1 deaths per 100 waitlist years. Short-term survival continued to improve, with a 6-month death rate of 6.6% and a 1-year death rate of 10.8% among recipients in 2015 compared with 8.0% and 13.3%, respectively, among recipients in 2014. Long-term survival rates remained unchanged; 55.6% of recipients were alive at 5 years. In 2016, 23 new candidates aged 0-11 years were added to the waiting list and 16 lung transplants were performed. Incidence of posttransplant mortality for lung transplant recipients aged 0-11 years who underwent transplant in 2014-2015 was 13.8% 1 at 6 months and 19.6% at 1 year. Changes in waitlist and transplant demographic features continued to evolve following implementation of the revised lung allocation score in 2015. Some early trends that may be attributable to the revised LAS are shorter waiting times, stabilization of the number of group D candidates listed for transplant, and convergence of LAS with lower prevalence of extremely high scores.