Molecular rectification induced by magnetization alignment in organic-ferromagnetic devices.

Spin-dependent transport in ferromagnet/organic-ferromagnet/ferromagnet junctions is investigated theoretically under different alignment of magnetization orientations. The results demonstrate a significant current rectification at low bias voltages, and the rectifying direction relies on the relative magnetization orientation in each component. The orbital analysis demonstrates two underlying mechanisms for the rectification, the slight structural asymmetry of the molecule from spin radicals and distinct spin match between conducting electrons and the magnetic molecule upon the reversal of bias. The latter is responsible for the strong low-bias rectification and relies on the magnetization alignment. The effects of parameter strength, temperature and size on the rectification are discussed. This work explores a new route to achieve high-performance molecular rectifiers operating at low bias with controlled rectifying direction.

[Analysis of risk factors for venous thromboembolism in patients with polycythemia vera and establishment of a prediction model].

Objective: To investigate the risk factors of venous thrombosis in patients with polycythemia vera (PV) and establish a prediction model for venous thrombosis. Methods: PV patients with JAK2V617F gene mutation positive in the Second Hospital of Tianjin Medical University from September 2017 to November 2023 were retrospectively included. The patients were divided into groups according to whether they had venous thrombosis. After matching age and gender factors with propensity scores, 102 patients were included in the venous thrombosis group [46 males, 56 females, with a median age M (Q1, Q3) of 52 (44, 60) years] and 204 cases were included in the group without venous thrombosis [92 males, 112 females, with a median age of 52 (44, 59) years]. The clinical and laboratory characteristics, disease progression and incidence of gene mutation were compared between the two groups. The follow-up cohort ended on November 20, 2023, with a median follow-up [M (Q1, Q3)] of 11 (1, 53) years. Multivariate Cox risk model was used to analyze the influencing factors of venous thrombosis in PV patients, and establish a scoring system for the venous thrombosis risk factor prediction model of PV patients. Receiver operating characteristic (ROC) curve was used to evaluate the predictive efficiency of the model. Results: Hemoglobin concentration, the ratio of hematopoietic volume≥55%, neutrophil to lymphocyte ratio≥5, hypertension, subcostal spleen≥5 cm and secondary myelofibrosis in venous thrombosis group were higher than those in non-venous thrombosis group (all P<0.05). In addition, the proportion of history of thromboembolism, V617F gene mutation load (V617F%)≥50%, diabetes mellitus, ASXL1 mutation and secondary reticular silver staining≥3 in the venous thrombosis group were higher than those in the non-venous thrombosis group (all P<0.05). The proportion of PV patients with 3 or more gene mutations was 44.1% (45/102) in venous thrombosis group, which was higher than that of PV patients without venous thrombosis 29.9% (61/204) (P=0.014). The proportion of ASXL1 gene mutation in venous thrombosis group was 17.6% (18/102), which was higher than the 4.9% (10/204) in non-venous thrombosis group (P<0.001). Multivariate Cox risk model analysis showed that previous thromboembolism history (HR=2.031, 95%CI: 1.297-3.179, P=0.002), V617F%≥50% (HR=2.141, 95%CI: 1.370-3.347, P=0.001), ASXL1 mutation (HR=4.632, 95%CI: 1.497-14.336, P=0.008), spleen subcostal≥5 cm (HR=1.771, 95%CI: 1.047-2.996, P=0.033) are the risk factors of venous thrombosis in PV patients. According to HR values, a score system for predicting risk of venous thrombosis in PV patients was established: previous history of thromboembolism, V617F%≥50% and spleen subcostoal≥5 cm were assigned 1 point respectively, and ASXL1 mutation was assigned 2 points. Low risk group: score 0, medium risk group: score 1-2, high risk group: score≥3. The ROC curve analysis of the model for predicting venous thrombosis in PV patients showed that the area under the curve (AUC) was 0.807 (95%CI: 0.755-0.860), with the sensitivity of 88.2% and the specificity of 59.8% when the Youden index was 0.48. Conclusions: Previous thromboembolism history, V617F%≥50%, ASXL1 mutation, spleen subcostoal≥5 cm are risk factors of venous thrombosis in PV patients. The established prediction model has good prediction efficiency.

[Research advances in the non-invasive diagnosis of metabolic dysfunction-associated fatty liver disease based on magnetic resonance technology].

Metabolic dysfunction-associated fatty liver disease is becoming the most common cause of chronic liver disease worldwide, with a disease spectrum including simple steatosis, steatohepatitis, hepatic fibrosis/cirrhosis, and liver cancer. Most metabolic dysfunction-associated fatty liver diseases progress slowly, but steatohepatitis, especially in patients accompanied by significant liver fibrosis, has a significantly increased risk of adverse liver disease outcomes and all-cause death. Therefore, early-stage identification of medium-and high-risk groups carried out by stratified management has important clinical significance. Pathological diagnosis is the gold standard for diagnosing steatohepatitis and liver fibrosis. However, its invasiveness, sampling errors, and unsuitability for dynamic monitoring limit its clinical application. In recent years, a large number of non-invasive diagnostic methods based on somatology, serology, and imaging have shown great development prospects in order to meet the clinical needs of assessing disease severity and risk stratification. This article reviews and summarizes the application and progress of magnetic resonance imaging technology in the non-invasive diagnosis of metabolic dysfunction-associated fatty liver disease.

[Analysis and summary of clinical characteristics of 289 patients with paroxysmal nocturnal hemoglobinuria in Zhejiang Province].

Objective: To further improve the understanding of paroxysmal nocturnal hemoglobinuria (PNH), we retrospectively analyzed and summarized the clinical characteristics, treatment status, and survival status of patients with PNH in Zhejiang Province. Methods: This study included 289 patients with PNH who visited 20 hospitals in Zhejiang Province. Their clinical characteristics, comorbidity, laboratory test results, and medications were analyzed and summarized. Results: Among the 289 patients with PNH, 148 males and 141 females, with a median onset age of 45 (16-87) years and a peak onset age of 20-49 years (57.8% ). The median lactic dehydrogenase (LDH) level was 1 142 (604-1 925) U/L. Classified by type, 70.9% (166/234) were classical, 24.4% (57/234) were PNH/bone marrow failure (BMF), and 4.7% (11/234) were subclinical. The main clinical manifestations included fatigue or weakness (80.8%, 235/289), dizziness (73.4%, 212/289), darkened urine color (66.2%, 179/272), and jaundice (46.2%, 126/270). Common comorbidities were hemoglobinuria (58.7% ), renal dysfunction (17.6% ), and thrombosis (15.0% ). Moreover, 82.3% of the patients received glucocorticoid therapy, 70.9% required blood transfusion, 30.7% used immunosuppressive agents, 13.8% received anticoagulant therapy, and 6.3% received allogeneic hematopoietic stem cell transplantation. The 10-year overall survival (OS) rate was 84.4% (95% CI 78.0% -91.3% ) . Conclusion: Patients with PNH are more common in young and middle-aged people, with a similar incidence rate between men and women. Common clinical manifestations include fatigue, hemoglobinuria, jaundice, renal dysfunction, and recurrent thrombosis. The 10-year OS of this group is similar to reports from other centers in China.