Organs recovered from donors after circulatory death (DCD) suffer warm ischemia before cold storage which may prejudice graft survival and result in a greater risk of complications after transplant. ...A period of normothermic regional perfusion (NRP) in the donor may reverse these effects and improve organ function. Twenty‐one NRP retrievals from Maastricht category III DCD donors were performed at three UK centers. NRP was established postasystole via aortic and caval cannulation and maintained for 2 h. Blood gases and biochemistry were monitored to assess organ function. Sixty‐three organs were recovered. Forty‐nine patients were transplanted. The median time from asystole to NRP was 16 min (range 10–23 min). Thirty‐two patients received a kidney transplant. The median cold ischemia time was 12 h 30 min (range 5 h 25 min–18 h 22 min). The median creatinine at 3 and 12 months was 107 µmol/L (range 72–222) and 121 µmol/L (range 63–157), respectively. Thirteen (40%) recipients had delayed graft function and four lost the grafts. Eleven patients received a liver transplant. The first week median peak ALT was 389 IU/L (range 58–3043). One patient had primary nonfunction. Two combined pancreas–kidney transplants, one islet transplant and three double lung transplants were performed with primary function. NRP in DCD donation facilitates organ recovery and may improve short‐term outcomes.
This study shows that the use of normothermic regional perfusion for organ recovery from controlled donation after circulatory death leads to an increased organ recovery rate and may improve short‐term transplant outcomes.
Over the course of the last century, organ transplantation has overcome major technical limitations to become the success it is today. The breakthroughs include developing techniques for vascular ...anastomoses, managing the immune response (initially by avoiding it with the use of identical twins and subsequently controlling it with chemical immunosuppressants), and devising preservation solutions that enable prolonged periods of ex vivo storage while preserving function. One challenge that has remained from the outset is to overcome the shortage of suitable donor organs. The results of organ transplantation continue to improve, both as a consequence of the above innovations and the improvements in peri- and postoperative management. This review describes some of the achievements and challenges of organ transplantation.
Atmospheric warming is intensifying glacier melting and
glacial-lake development in High Mountain Asia (HMA), and this could
increase glacial-lake outburst flood (GLOF) hazards and impact water
...resources and hydroelectric-power management. There is therefore a pressing
need to obtain comprehensive knowledge of the distribution and area of
glacial lakes and also to quantify the variability in their sizes and types
at high resolution in HMA. In this work, we developed an HMA glacial-lake
inventory (Hi-MAG) database to characterize the annual coverage of glacial
lakes from 2008 to 2017 at 30 m resolution using Landsat satellite imagery.
Our data show that glacial lakes exhibited a total area increase of
90.14 km2 in the period 2008–2017, a +6.90 % change relative to
2008 (1305.59±213.99 km2). The annual increases in the number
and area of lakes were 306 and 12 km2, respectively, and the greatest
increase in the number of lakes occurred at 5400 m elevation, which
increased by 249. Proglacial-lake-dominated areas, such as the
Nyainqêntanglha and central Himalaya, where more than half of the
glacial-lake area (summed over a 1∘ × 1∘
grid) consisted of proglacial lakes, showed obvious lake-area expansion.
Conversely, some regions of eastern Tibetan mountains and Hengduan Shan,
where unconnected glacial lakes occupied over half of the total lake area in
each grid, exhibited stability or a slight reduction in lake area. Our
results demonstrate that proglacial lakes are a main contributor to recent
lake evolution in HMA, accounting for 62.87 % (56.67 km2) of the
total area increase. Proglacial lakes in the Himalaya ranges alone accounted
for 36.27 % (32.70 km2) of the total area increase. Regional
geographic variability in debris cover, together with trends in warming and
precipitation over the past few decades, largely explains the current
distribution of supraglacial- and proglacial-lake area across HMA. The Hi-MAG
database is available at https://doi.org/10.5281/zenodo.4275164
(Chen et al., 2020), and it can be used for studies of the complex interactions between glaciers, climate and glacial lakes, studies of GLOFs, and water resources.
The stochastic evolution of quantum systems during measurement is arguably the most enigmatic feature of quantum mechanics. Measuring a quantum system typically steers it towards a classical state, ...destroying the coherence of an initial quantum superposition and the entanglement with other quantum systems. Remarkably, the measurement of a shared property between non-interacting quantum systems can generate entanglement, starting from an uncorrelated state. Of special interest in quantum computing is the parity measurement, which projects the state of multiple qubits (quantum bits) to a state with an even or odd number of excited qubits. A parity meter must discern the two qubit-excitation parities with high fidelity while preserving coherence between same-parity states. Despite numerous proposals for atomic, semiconducting and superconducting qubits, realizing a parity meter that creates entanglement for both even and odd measurement results has remained an outstanding challenge. Here we perform a time-resolved, continuous parity measurement of two superconducting qubits using the cavity in a three-dimensional circuit quantum electrodynamics architecture and phase-sensitive parametric amplification. Using postselection, we produce entanglement by parity measurement reaching 88 per cent fidelity to the closest Bell state. Incorporating the parity meter in a feedback-control loop, we transform the entanglement generation from probabilistic to fully deterministic, achieving 66 per cent fidelity to a target Bell state on demand. These realizations of a parity meter and a feedback-enabled deterministic measurement protocol provide key ingredients for active quantum error correction in the solid state.
A deadly cascade
A catastrophic landslide in Uttarakhand state in India on February 2021 damaged two hydropower plants, and more than 200 people were killed or are missing. Shugar
et al.
describe the ...cascade of events that led to this disaster. A massive rock and ice avalanche roared down a Himalayan valley, turning into a deadly debris flow upstream from the first of the two hydropower plants. The sequence of events highlights the increasing risk in the Himalayas caused by increased warming and development.
Science
, abh4455, this issue p.
300
A cascade of events starting with a massive avalanche eventually triggered a deadly debris flow in the Indian Himalaya.
On 7 February 2021, a catastrophic mass flow descended the Ronti Gad, Rishiganga, and Dhauliganga valleys in Chamoli, Uttarakhand, India, causing widespread devastation and severely damaging two hydropower projects. More than 200 people were killed or are missing. Our analysis of satellite imagery, seismic records, numerical model results, and eyewitness videos reveals that ~27 × 10
6
cubic meters of rock and glacier ice collapsed from the steep north face of Ronti Peak. The rock and ice avalanche rapidly transformed into an extraordinarily large and mobile debris flow that transported boulders greater than 20 meters in diameter and scoured the valley walls up to 220 meters above the valley floor. The intersection of the hazard cascade with downvalley infrastructure resulted in a disaster, which highlights key questions about adequate monitoring and sustainable development in the Himalaya as well as other remote, high-mountain environments.
After psychological trauma, recurrent intrusive visual memories may be distressing and disruptive. Preventive interventions post trauma are lacking. Here we test a behavioural intervention after ...real-life trauma derived from cognitive neuroscience. We hypothesized that intrusive memories would be significantly reduced in number by an intervention involving a computer game with high visuospatial demands (Tetris), via disrupting consolidation of sensory elements of trauma memory. The Tetris-based intervention (trauma memory reminder cue plus c. 20 min game play) vs attention-placebo control (written activity log for same duration) were both delivered in an emergency department within 6 h of a motor vehicle accident. The randomized controlled trial compared the impact on the number of intrusive trauma memories in the subsequent week (primary outcome). Results vindicated the efficacy of the Tetris-based intervention compared with the control condition: there were fewer intrusive memories overall, and time-series analyses showed that intrusion incidence declined more quickly. There were convergent findings on a measure of clinical post-trauma intrusion symptoms at 1 week, but not on other symptom clusters or at 1 month. Results of this proof-of-concept study suggest that a larger trial, powered to detect differences at 1 month, is warranted. Participants found the intervention easy, helpful and minimally distressing. By translating emerging neuroscientific insights and experimental research into the real world, we offer a promising new low-intensity psychiatric intervention that could prevent debilitating intrusive memories following trauma.
Silicon is more than the dominant material in the conventional microelectronics industry: it also has potential as a host material for emerging quantum information technologies. Standard fabrication ...techniques already allow the isolation of single electron spins in silicon transistor-like devices. Although this is also possible in other materials, silicon-based systems have the advantage of interacting more weakly with nuclear spins. Reducing such interactions is important for the control of spin quantum bits because nuclear fluctuations limit quantum phase coherence, as seen in recent experiments in GaAs-based quantum dots. Advances in reducing nuclear decoherence effects by means of complex control still result in coherence times much shorter than those seen in experiments on large ensembles of impurity-bound electrons in bulk silicon crystals. Here we report coherent control of electron spins in two coupled quantum dots in an undoped Si/SiGe heterostructure and show that this system has a nuclei-induced dephasing time of 360 nanoseconds, which is an increase by nearly two orders of magnitude over similar measurements in GaAs-based quantum dots. The degree of phase coherence observed, combined with fast, gated electrical initialization, read-out and control, should motivate future development of silicon-based quantum information processors.
Glacier recession driven by climate change produces glacial lakes, some of which are hazardous. Our study assesses the evolution of three of the most hazardous moraine-dammed proglacial lakes in the ...Nepal Himalaya—Imja, Lower Barun, and Thulagi. Imja Lake (up to 150 m deep; 78.4 × 106 m3 volume; surveyed in October 2014) and Lower Barun Lake (205 m maximum observed depth; 112.3 × 106 m3 volume; surveyed in October 2015) are much deeper than previously measured, and their readily drainable volumes are slowly growing. Their surface areas have been increasing at an accelerating pace from a few small supraglacial lakes in the 1950s/1960s to 1.33 km2 and 1.79 km2 in 2017, respectively. In contrast, the surface area (0.89 km2) and volume of Thulagi lake (76 m maximum observed depth; 36.1 × 106 m3; surveyed in October 2017) has remained almost stable for about two decades. Analyses of changes in the moraine dams of the three lakes using digital elevation models (DEMs) quantifies the degradation of the dams due to the melting of their ice cores and hence their natural lowering rates as well as the potential for glacial lake outburst floods (GLOFs). We examined the likely future evolution of lake growth and hazard processes associated with lake instability, which suggests faster growth and increased hazard potential at Lower Barun lake.
Central Neuropathic Pain Syndromes Watson, James C; Sandroni, Paola
Mayo Clinic proceedings,
03/2016, Letnik:
91, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Chronic pain is common in patients with neurologic complications of a central nervous system insult such as stroke. The pain is most commonly musculoskeletal or related to obligatory overuse of ...neurologically unaffected limbs. However, neuropathic pain can result directly from the central nervous system injury. Impaired sensory discrimination can make it challenging to differentiate central neuropathic pain from other pain types or spasticity. Central neuropathic pain may also begin months to years after the injury, further obscuring recognition of its association with a past neurologic injury. This review focuses on unique clinical features that help distinguish central neuropathic pain. The most common clinical central pain syndromes-central poststroke pain, multiple sclerosis-related pain, and spinal cord injury-related pain-are reviewed in detail. Recent progress in understanding of the pathogenesis of central neuropathic pain is reviewed, and pharmacological, surgical, and neuromodulatory treatments of this notoriously difficult to treat pain syndrome are discussed.
Livers retrieved after circulatory death are associated with an increased incidence of primary nonfunction, early allograft dysfunction, and biliary strictures. The authors report a case of ...preimplant normothermic perfusion of a suboptimal liver from a 57‐year‐old donor after circulatory death who had been hospitalized for 9 days; predonation alanine transaminase level was 63 IU/L, and the period from withdrawal of life‐supporting treatment to circulatory arrest was 150 minutes. After 5 hours of static cold storage, the liver was subject to normothermic machine perfusion with a plasma‐free red cell–based perfusate. Perfusate lactate level fell from 7.2 to 0.3 mmol/L within 74 minutes of ex situ perfusion, at which point perfusate alanine transaminase level was 1152 IU/L and urea concentration was 9.4 mmol/L. After 132 minutes, normothermic perfusion was stopped and implantation begun. After transplantation, the patient made an uneventful recovery and was discharged on day 8; liver biochemistry was normal by day 19 and has remained normal thereafter. Donor common bile duct excised at implantation showed preservation of peribiliary glands, and cholangiography 6 months posttransplantation showed no evidence of cholangiopathy. Preimplant ex situ normothermic perfusion of the liver appears to be a promising way to evaluate a marginal liver before transplantation and may modify the response to ischemia.
The authors report a liver transplant where ex situ normothermic machine perfusion was used to reduce cold ischemia and permit functional assessment of a donation after circulatory death liver before implantation.
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