Engineering Spin-Orbit Interactions in Silicon Qubits at the Atomic-Scale.

Spin-orbit interactions arise whenever the bulk inversion symmetry and/or structural inversion symmetry of a crystal is broken providing a bridge between a qubit's spin and orbital degree of freedom. While strong interactions can facilitate fast qubit operations by all-electrical control, they also provide a mechanism to couple charge noise thereby limiting qubit lifetimes. Previously believed to be negligible in bulk silicon, recent silicon nano-electronic devices have shown larger than bulk spin-orbit coupling strengths from Dresselhaus and Rashba couplings. Here, it is shown that with precision placement of phosphorus atoms in silicon along the [110] direction (without inversion symmetry) or [111] direction (with inversion symmetry), a wide range of Dresselhaus and Rashba coupling strength can be achieved from zero to 1113 × 10-13eV-cm. It is shown that with precision placement of phosphorus atoms, the local symmetry (C2v, D2d, and D3d) can be changed to engineer spin-orbit interactions. Since spin-orbit interactions affect both qubit operation and lifetimes, understanding their impact is essential for quantum processor design.

Trends in category and grade for therapeutic plasma exchange in the latest guideline on therapeutic apheresis by the American Society for Apheresis: Hurdles in pursuing evidence-based medicine.

BACKGROUND AND OBJECTIVES: The Writing Committee of American Society for Apheresis released the ninth edition of guidelines for therapeutic apheresis in 2023. Categories have been a part of the guidelines since the first edition, and the grading system was introduced in the fifth edition, with updates in every new edition. In this study, we investigated the category and grade change trends through the latest five editions, focusing on therapeutic plasma exchange, to suggest future directions as part of evidence-based medicine. MATERIALS AND METHODS: Categories and grades for therapeutic plasma exchange (TPE) were collected and analysed from the fifth through ninth editions. We aligned classification changes to the ninth edition's clinical context and compared its categories and grades with those introduced in the guideline. RESULTS: Among 166 total indications in the ninth edition, 118 included TPE procedure, either as a sole treatment or as one of the therapeutic apheresis techniques. The total number of indications changed, but Category III remained predominant throughout the editions. Similarly, Grade 2C consistently emerged as the most prevalent grade. Notably, 24 cases had grade changes. Of the 16 cases with evidence quality changes, the quality weakened in six and improved in 10. Evidence levels were not improved throughout the study period for 102 clinical conditions. CONCLUSION: To address gaps in evidence quality, international collaboration is imperative to establish comprehensive large-scale studies or randomized controlled trials. This will refine the use of therapeutic apheresis, including TPE, to foster evidence-based advancements in clinical practice.

Atomic Engineering of Molecular Qubits for High-Speed, High-Fidelity Single Qubit Gates.

Universal quantum computing requires fast single- and two-qubit gates with individual qubit addressability to minimize decoherence errors during processor operation. Electron spin qubits using individual phosphorus donor atoms in silicon have demonstrated long coherence times with high fidelities, providing an attractive platform for scalable quantum computing. While individual qubit addressability has been demonstrated by controlling the hyperfine interaction between the electron and nuclear wave function in a global magnetic field, the small hyperfine Stark coefficient of 0.34 MHz/MV m-1 achieved to date has limited the speed of single quantum gates to ∼42 µs to avoid rotating neighboring qubits due to power broadening from the antenna. The use of molecular 2P qubits with more than one donor atom has not only demonstrated fast (0.8 ns) two-qubit SWAP gates and long spin relaxation times of ∼30 s but provides an alternate way to achieve high selectivity of the qubit resonance frequency. Here, we show in two different devices that by placing the donors with comparable interatomic spacings (∼0.8 nm) but along different crystallographic axes, either the [110] or [310] orientations using STM lithography, we can engineer the hyperfine Stark shift from 1 MHz/MV m-1 to 11.2 MHz/MV m-1, respectively, a factor of 10 difference. NEMO atomistic calculations show that larger hyperfine Stark coefficients of up to ∼70 MHz/MV m-1 can be achieved within 2P molecules by placing the donors ≥5 nm apart. When combined with Gaussian pulse shaping, we show that fast single qubit gates with 2π rotation times of 10 ns and ∼99% fidelity single qubit operations are feasible without affecting neighboring qubits. By increasing the single qubit gate time to ∼550 ns, two orders of magnitude faster than previously measured, our simulations confirm that >99.99% single qubit control fidelities are achievable.

Evaluation of an eight marker-panel including long mononucleotide repeat markers to detect microsatellite instability in colorectal, gastric, and endometrial cancers.

BACKGROUND: Accurate determination of microsatellite instability (MSI) status is critical for optimal treatment in cancer patients. Conventional MSI markers can sometimes display subtle shifts that are difficult to interpret, especially in non-colorectal cases. We evaluated an experimental eight marker-panel including long mononucleotide repeat (LMR) markers for detection of MSI. METHODS: The eight marker-panel was comprised of five conventional markers (BAT-25, BAT-26, NR-21, NR-24, and NR-27) and three LMR markers (BAT-52, BAT-59 and BAT-62). MSI testing was performed against 300 specimens of colorectal, gastric, and endometrial cancers through PCR followed by capillary electrophoresis length analysis. RESULTS: The MSI testing with eight marker-panel showed 99.3% (295/297) concordance with IHC analysis excluding 3 MMR-focal deficient cases. The sensitivity of BAT-59 and BAT-62 was higher than or comparable to that of conventional markers in gastric and endometrial cancer. The mean shift size was larger in LMR markers compared to conventional markers for gastric and endometrial cancers. CONCLUSIONS: The MSI testing with eight maker-panel showed comparable performance with IHC analysis. The LMR markers, especially BAT-59 and BAT-62, showed high sensitivity and large shifts which can contribute to increased confidence in MSI classification, especially in gastric and endometrial cancers. Further study is needed with large number of samples for the validation of these LMR markers.

Clinical significances and distribution of unexpected antibodies found in infants.

INTRODUCTION: The unexpected antibody test is an essential for ensuring the safety of blood transfusions. In infants, different pre-transfusion tests and transfusion strategies are needed due to their immature antigen/antibody system. This study aims to analyze the pattern of unexpected antibodies and their clinical significance in infants. METHODS: A retrospective analysis was conducted on the results of unexpected antibody identification tests performed on infants under one year of age at Asan Medical Center from 1999 to 2022. Patients' unexpected antibody identification test results and clinical information were investigated. The results of unexpected antibody identification and phenotype of each patient's mother were collected. RESULTS: 45 cases of antibody results were studied. 25 cases were found in infants under 4 months of age, and 18 cases (76%) were associated with hemolytic disease of the fetus and newborn (HDFN). The most common unexpected antibody in infants was anti-M (17 cases). There was one case of severe HDFN caused by anti-M. In 10 cases, anti-E and anti-c were found together, and 9 of these cases were associated with HDFN. There were four cases with a history of previous transfusion. CONCLUSIONS: Non-ABO antibodies found in infants showed a different pattern compared to adults. Interpreting unexpected antibody tests in infants, it is important to consider the clinical status of the infant and the test results of the mother, due to possibility of HDFN. To our knowledge, this is the first study to reveal the distribution and clinical significances of unexpected antibodies found in infants in Korea.

Investigation of variables affecting the immunogenicity of blood group antigens using a calculation formula.

Previous studies on the immunogenicity of blood group antigens have utilized a formula incorporating antigen frequencies and relative frequencies of unexpected antibodies to the corresponding antigens. This study was aimed at investigating other variables potentially affecting the estimation of immunogenicity using this formula. We examined the effect of multiple transfusions, as there are more chance for a recipient to receive repeated transfusions rather than only once; the effect of antigen density, which may vary depending on homozygote/heterozygote; and the effect of unreliability of the observed frequency of rare antibodies and antigens. For multiple transfusions, the expected antibody frequency increased as the number of transfusions increased. For antigen density, the immunogenicity was falsely low for the low-prevalence antigen, and this tendency intensified as the effect of antigen density increased. Expected antibody frequencies were significantly affected by the uncertainties caused by estimation of small numbers. This study showed that the effects of various factors on the immunogenicity of blood group antigens depended on the antigen frequency. Estimating the immunogenicity of blood group antigens requires acknowledging the diverse factors that can affect it and interpreting the findings with caution.

Relative immunogenicity of blood group antigens: First report in a Korean population.

BACKGROUND: The immunogenicity of a blood group antigen is a measure of its likelihood of inducing alloantibodies. Although the immunogenicity of blood group antigens has been analyzed in Caucasian populations, immunogenicity to date has not been analyzed in Asian subjects. The present study therefore evaluated the relative immunogenicity of blood group antigens in a Korean population. STUDY DESIGN AND METHODS: All available data of unexpected antibody identification tests performed at Asan Medical Center between 1997 and 2021 were analyzed. The relative immunogenicity of a blood group antigen relative to K antigen was calculated based on relative numbers of alloantibodies and the probabilities of antigen-negative recipients receiving antigen-positive RBC units. RESULTS: A total of 3898 antibody identification results were included, with 1632 (41.9 %) from male patients. The ranking of antigen immunogenicity was: E > c > e > C > K > Jk(a) > Lu(a) > S > Fy(a) > Fy(b) > Jk(b) > Di(b) > Di(a) in the total population and E > c > e > C > Jk(a) > Fy(a) > Fy(b) > S > K > Lu(a) > Jk(b) > Di(b) > Di(a) in male patients. DISCUSSION: The rank order of immunogenicity for blood group antigens in this study provides information about relative immunogenecity in Koreans. These findings also provide supporting evidence regarding antigen selection for extended antigen-matched transfusions in recipients of multiple transfusions.

Ramped measurement technique for robust high-fidelity spin qubit readout.

State preparation and measurement of single-electron spin qubits typically rely on spin-to-charge conversion where a spin-dependent charge transition of the electron is detected by a coupled charge sensor. For high-fidelity, fast readout, this process requires that the qubit energy is much larger than the temperature of the system limiting the temperature range for measurements. Here, we demonstrate an initialization and measurement technique that involves voltage ramps rather than static voltages allowing us to achieve state-to-charge readout fidelities above 99% for qubit energies almost half that required by traditional methods. This previously unidentified measurement technique is highly relevant for achieving high-fidelity electron spin readout at higher temperature operation and offers a number of pragmatic benefits compared to traditional energy-selective readout such as real-time dynamic feedback and minimal alignment procedures.

Laboratory support of ABO antibody monitoring for ABO-incompatible solid organ transplantation.

The accurate measurement of ABO antibodies is essential for successful ABO-incompatible solid organ transplantation. Titration using two-fold dilution is considered a standard method and is applied in most laboratories. However, this titration method has inherent limitations, including differences in methods between laboratories, a lack of standardization, its semiquantitative nature, and the difficulty of considering the results to be representative of the in vivo activity of ABO antibodies. Various measurement methods other than titration have been developed, and new methods continue to be introduced. Physicians and laboratory specialists who are involved in ABO-incompatible solid organ transplantation need to fully understand these methods for optimal patient management.

A New Trial to Measure ABO Antibodies Using Complement-Dependent Cytotoxicity.

Background and objectives: The ABO antibody (Ab) titration tests are used in monitoring in ABO-incompatible (ABOi) solid organ transplantation (SOT). However, currently developed ABO Ab tests show Ab binding reactions. This study attempted to measure ABO Ab level using complement-dependent cytotoxicity (CDC). Materials and methods: We studied 93 blood group O serum samples from patients who underwent ABOi SOT from January 2019 to May 2021. Patients' sera were incubated with A1 or B cells and added to a human complement solution. Supernatants were collected after centrifugation, and free hemoglobin (Hb) was measured by spectrophotometry. We converted plasma Hb value to hemolysis (%), which were compared with ABO Ab titer. Results: We found a mild correlation between hemolysis and ABO Ab titers. In simple regression analysis, the correlation coefficients were within 0.3660−0.4968 (p < 0.0001) before transplantation. In multiple linear regression analysis, anti-A hemolysis (%) was higher in immunoglobulin M (IgM) (ß = 12.9) than in immunoglobulin G (IgG) (ß = −3.4) (R2 = 0.5216). Anti-B hemolysis was higher in IgM (ß = 8.7) than in IgG (ß = 0.0) (R2 = 0.5114). There was a large variation in hemolysis within the same Ab titer. Conclusions: CDC can be used in a new trial for ABO Ab measurement. Furthermore, IgM rather than IgG seems to play a significant role in vivo activity, consistent with previous knowledge. Thus, this study may help in the development of the ABO Ab titration supplement test for post-transplant treatment policy establishment and pre-transplant desensitization.

Detection of anti-B antibodies in a patient with A1B blood group: A case report and literature review.

ABO antibodies occur naturally and usually exist as alloantibodies. They are the most clinically significant in cases of transfusions. However, there are very few reports on auto-anti-A or B. A 58-year-old man visited our hospital for evaluation of an inguinal mass. Blood typing was performed, while preparing the patient for an excisional biopsy. Forward and reverse typing showed a typical AB and A pattern. Results of the direct antiglobulin and unexpected antibody screening tests were negative. The serum did not react with AB3 cells. The biopsy revealed a diffuse large B-cell lymphoma. After completing four cycles of R-CHOP chemotherapy, the patient achieved complete remission. There were no anti-B antibodies found on repeat ABO typing. This report shares our experience on unexpected anti-B antibody findings in a patient with an A1B blood type. To the best of our knowledge, this is the first report of anti-B antibodies in a patient with an A1B blood type in Korea.

Comparison of Erythrocyte and Reticulocyte Indices for Evaluation of Iron Deficiency by Two Automated Hematologic Analyzers.

The reticulocyte hemoglobin content and hypochromic erythrocyte percentage offer advantages in evaluation of iron deficiency, especially in inflammatory conditions. The aim of this study was to evaluate the correlation of reticulocyte hemoglobin content (CHr, Ret-He) and hypochromic erythrocyte percentage (%HYPO, Hypo-He) between two automated hematologic analyzers. The CHr and %HYPO values were determined using the Advia 2021i (Siemens), while the Ret-He and Hypo-He levels were assessed using the XN-3000 (Sysmex). Data from a total of 971 cases and 834 patients were collected. For reticulocyte hemoglobin content, there was a good linear correlation between CHr and Ret-He (r = 0.857, p < 0.001). For percentage of hypochromic erythrocytes, there was a better correlation between the two measures when using a second-degree polynomial equation (Hypo-He* = 0.4818 - 0.0218 x %HYPO + 0.0069 x %HYPO2) (r = 0.786, p < 0.001).

Outcome of ABO-Incompatible Kidney Transplantation According to ABO Type of Transfused Plasma: Comparative Analysis Between "Universal" AB and Donor-Type Plasma.

OBJECTIVE: We compared the clinical outcomes of recipients of ABO-incompatible (ABOi) kidney transplantation (KT) according to the blood group of the plasma transfused. MATERIALS AND METHODS: We retrospectively analyzed the data of 60 recipients of ABOi-KT with blood type O and A or B donors. Demographic and clinical characteristics were compared between 2 groups of recipients: 1 group received AB plasma regardless of the donor's blood type (n = 30), and the other group received donor-type plasma (n = 30). RESULTS: There were no significant differences between the groups in terms of demographic characteristics. Transfusion of donor-type plasma was noninferior to transfusion of type AB plasma in terms of both rejection-free survival and rejection rate (P = .455, P = .335). CONCLUSION: There was no significant prognostic difference between the 2 groups. In terms of blood supply and inventory management, we suggest that the blood group of the plasma should match the donor's type.

Questionnaire Survey on Current Red Blood Cell Transport and Storage in Korea for Reducing Wastage.

BACKGROUND: To ensure safe red blood cell (RBC) transfusion practice, it is important to comply with storage and transport requirements of RBC units. We conducted a comprehensive survey on the practice of RBC transport and storage to explore the awareness of and compliance with the 30-minute rule, the current status of RBC unit transport, and possible utility of temperature indicators (TIs) to reduce RBC wastage. METHODS: From June to August of 2019, 64 blood bank physicians (14 questions) in 64 secondary- and tertiary-care hospitals and 673 nurses (13 questions) in 42 tertiary-care hospitals replied to a questionnaire survey. The results of the survey were analyzed with descriptive statistics. RESULTS: Among the physicians surveyed, 97.0% (N=62) of hospitals had transfusion guidelines in place. The RBC wastage in 2018 ranged from less than five units to more than 200 units. Among the nurses surveyed, 99.4% (N=669) were aware of and complied with the 30-minute rule; 13.5% (N=91) of the nurses had experience of RBC wastage due to violation of the 30-minute rule. Both physicians (67%, N=43) and nurses (83.1%, N=559) responded that TIs would help reduce RBC wastage. CONCLUSIONS: This is the first survey on the practices related to RBC transport and storage in Korea. This study provides fundamental data on current practice for the blood cold chain, insights into RBC wastage, and highlights the utility of TIs.

Is Cryoprecipitate-Reduced Plasma an Efficacious Replacement Fluid for Therapeutic Plasma Exchange for Patients with Thrombotic Microangiopathy? A Single-Center Retrospective Experience.

OBJECTIVE: We designed a study to compare the efficacy of cryoprecipitate-reduced plasma (CRP) and fresh frozen plasma (FFP), at the level of individual sessions, for treating refractory thrombotic microangiopathy (TMA) with therapeutic plasma exchange (TPE). MATERIALS AND METHODS: Platelet counts (× 10³/µL) and lactate dehydrogenase (LD; IU/L) levels were measured before and after each session. We compared the mean-percentage and absolute changes in platelet count and LD after each TPE session. RESULTS: The data from 33 patients treated for TMA between 2009 and 2018 were collected for this study. Both absolute and percentage increases in the platelet count were statistically significant (P = .003 and P = .011, respectively) when CRP was used. However, when patients were divided into subgroups according to specific diagnosis, no significant differences were found among the groups, except in terms of the absolute platelet count increase in the thrombotic thrombocytopenic purpura group (P <.001). CONCLUSION: The platelet count increase was higher when patients received CRP than when they received FFP. We found that CRP may be a rescue option for patients with refractory TMA.