Atropisomeric Carboxylic Acids Synthesis via Nickel-Catalyzed Enantioconvergent Carboxylation of Aza-Biaryl Triflates with CO2.

Upgrading CO2 to value-added chiral molecules via catalytic asymmetric C-C bond formation is a highly important yet challenging task. Although great progress on the formation of centrally chiral carboxylic acids has been achieved, catalytic construction of axially chiral carboxylic acids with CO2 has never been reported to date. Herein, we report the first catalytic asymmetric synthesis of axially chiral carboxylic acids with CO2, which is enabled by nickel-catalyzed dynamic kinetic asymmetric reductive carboxylation of racemic aza-biaryl triflates. A variety of important axially chiral carboxylic acids, which are valuable but difficult to obtain via catalysis, are generated in an enantioconvergent version. This new methodology features good functional group tolerance, easy to scale-up, facile transformation and avoids cumbersome steps, handling organometallic reagents and using stoichiometric chiral materials. Mechanistic investigations indicate a dynamic kinetic asymmetric transformation process induced by chiral nickel catalysis.

Nanoscale Gap-Plasmon-Enhanced Superconducting Photon Detectors at Single-Photon Level.

With a growing demand for detecting light at the single-photon level in various fields, researchers are focused on optimizing the performance of superconducting single-photon detectors (SSPDs) by using multiple approaches. However, input light coupling for visible light has remained a challenge in the development of efficient SSPDs. To overcome these limitations, we developed a novel system that integrates NbN superconducting microwire photon detectors (SMPDs) with gap-plasmon resonators to improve the photon detection efficiency to 98% while preserving all detector performance features, such as polarization insensitivity. The plasmonic SMPDs exhibit a hot-belt effect that generates a nonlinear photoresponse in the visible range operated at 9 K (∼0.64Tc), resulting in a 233-fold increase in phonon-electron interaction factor (γ) compared to pristine SMPDs at resonance under CW illumination. These findings open up new opportunities for ultrasensitive single-photon detection in areas like quantum information processing, quantum optics, imaging, and sensing at visible wavelengths.

Realizing High Brightness Quasi-2D Perovskite Light-Emitting Diodes with Reduced Efficiency Roll-Off via Multifunctional Interface Engineering.

Quasi-2D perovskites have recently flourished in the field of luminescence due to the quantum-confinement effect and the efficient energy transfer between different n phases resulting in exceptional optical properties. However, owing to the lower conductivity and poor charge injection, quasi-2D perovskite light-emitting diodes (PeLEDs) typically suffer from low brightness and high-efficiency roll-off at high current densities compared to 3D perovskite-based PeLEDs, which is undoubtedly one of the most critical issues in this field. In this work, quasi-2D PeLEDs with high brightness, reduced trap density, and low-efficiency roll-off are successfully demonstrated by introducing a thin layer of conductive phosphine oxide at the perovskite/electron transport layer interface. The results surprisingly show that this additional layer does not improve the energy transfer between multiple quasi-2D phases in the perovskite film, but purely improves the electronic properties of the perovskite interface. On the one hand, it passivates the surface defects of the perovskite film; on the other hand, it promotes electron injection and prevents hole leakage across this interface. As a result, the modified quasi-2D pure Cs-based device shows a maximum brightness of > 70,000 cd m-2 (twice that of the control device), a maximum external quantum efficiency (EQE) of > 10% and a much lower efficiency roll-off at high bias voltages.

[Effectiveness of autologous hematopoietic stem cell transplantation in the treatment of high-risk neuroblastoma in children: a single-center clinical study]. / å•ä¸­å¿ƒå„¿ç«¥é«˜å±ç¥žç»æ¯ç»†èƒžç˜¤è‡ªä½“é€ è¡€å¹²ç»†èƒžç§»æ¤çš„ç–—æ•ˆåˆ†æž.

OBJECTIVES: To investigate the effectiveness of high-dose chemotherapy combined with autologous hematopoietic stem cell transplantation (ASCT) in the treatment of children with high-risk neuroblastoma (NB). METHODS: A retrospective analysis was performed on 29 children with high-risk NB who were admitted to Shanghai Children's Hospital and were treated with high-dose chemotherapy combined with ASCT from January 2013 to December 2021, and their clinical features and prognosis were analyzed. RESULTS: Among the 29 children treated by high-dose chemotherapy combined with ASCT, there were 18 boys (62%) and 11 girls (38%), with a median age of onset of 36 (27, 59) months. According to the International Neuroblastoma Staging System, 6 children (21%) had stage III NB and 23 children (79%) had stage IV NB, and the common metastatic sites at initial diagnosis were bone in 22 children (76%), bone marrow in 21 children (72%), and intracalvarium in 4 children (14%). All 29 children achieved reconstruction of hematopoietic function after ASCT. After being followed up for a median time of 25 (17, 45) months, 21 children (72%) had continuous complete remission and 8 (28%) experienced recurrence. The 3-year overall survival rate and event-free survival rate were 68.9%±16.1% and 61.4%±14.4%, respectively. Presence of bone marrow metastasis, neuron-specific enolase ≥370 ng/mL and positive bone marrow immunophenotyping might reduce the 3-year event-free survival rate (P<0.05). CONCLUSIONS: Children with high-risk NB who have bone marrow metastasis at initial diagnosis tend to have a poor prognosis. ASCT combined with high-dose chemotherapy can effectively improve the prognosis of children with NB with a favorable safety profile.

Exploration of Clove Bud (Syzygium aromaticum) Essential Oil as a Novel Attractant against Bactrocera dorsalis (Hendel) and Its Safety Evaluation.

The oriental fruit fly Bactrocera dorsalis (Hendel) is a destructive polyphagous species that targets many economically important fruits and vegetables. The primary control of B. dorsalis relies mainly on the use of synthetic chemicals, and excessive use of these chemicals has adverse effects on both the environment and human health. Environmentally friendly management of pests involving plant essential oils is useful for controlling the populations of pests responsible for decreasing the yields and quality of crops. In the present study, we demonstrate that clove bud essential oil (CBEO) is strongly attractive to sexually mature males. Mature males responded to the CBEO differently throughout the day; the strongest response was elicited during the day and decreased at dusk. Virgin and mated mature males did not respond differently to CBEO. No obvious response behaviour to the CBEO was observed in two species of beneficial natural predator ladybirds. In addition, a cytotoxicity assessment demonstrated that CBEO is nontoxic to normal human and mouse cells. Based on our laboratory experiments, CBEO may serve as a promising, sustainable, and environmentally friendly attractant for B. dorsalis males; however, field experiments are needed to confirm this hypothesis.

Targeted next-generation sequencing identifies a novel nonsense mutation in ANK1 for hereditary spherocytosis: A case report.

BACKGROUND: Hereditary spherocytosis (HS) is characterized by anemia, jaundice, splenomegaly, and cholelithiasis, and is caused by abnormal genes encoding red blood cell membrane components. The most common mutations found in HS are in the ANK1 gene. CASE SUMMARY: A 4-mo-old girl was admitted to our hospital with pallor that had lasted for more than 2 mo. She presented with jaundice, anemia and splenomegaly. A heterozygous mutation of ANK1 (exon23: c.G2467T:p.E823X) was identified, and the mutation was determined to be autosomal dominant. This mutation is linked to the relatively serious anemia she had after birth; this anemia improved with age. CONCLUSION: The utilization of next-generation sequencing may assist with the accurate diagnosis of HS, especially in atypical cases.

Niobium nitride plasmonic perfect absorbers for tunable infrared superconducting nanowire photodetection.

Quantum technologies such as quantum computing and quantum cryptography exhibit rapid progress. This requires the provision of high-quality photodetectors and the ability to efficiently detect single photons. Hence, conventional avalanche photodiodes for single photon detection are not the first choice anymore. A better alternative are superconducting nanowire single photon detectors, which use the superconducting to normal conductance phase transition. One big challenge is to reduce the product between recovery time and detection efficiency. To address this problem, we enhance the absorption using resonant plasmonic perfect absorber effects, to reach near-100% absorption over small areas. This is aided by the high resonant absorption cross section and the angle insensitivity of plasmonic resonances. In this work we present a superconducting niobium nitride plasmonic perfect absorber structure and use its tunable plasmonic resonance to create a polarization dependent photodetector with near-100% absorption efficiency in the infrared spectral range. Further we fabricated a detector and investigated its response to an external light source. We also demonstrate the resonant plasmonic behavior which manifests itself through a polarization dependence detector response.

[Aerobic Granular Sludge Operation and Nutrient Removal Mechanism from Domestic Sewage in an Anaerobic/Aerobic Alternating Continuous Flow System].

Mature aerobic granular sludge was inoculated at room temperature in an anaerobic/aerobic alternating continuous flow system. The system consisted of two independent anaerobic and aerobic tanks. Actual domestic sewage was used as the influent to explore the influence of the gas intensity and hydraulic residence time on the continuous flow system. The results revealed that the conditions of a reflux ratio of 2, lower aeration intensity (0.6 mL·min-1), and proper hydraulic residence time (9 h) were more conducive to the removal of pollutants. Under such conditions, the average removal rate of TP was 80.43%, the average removal rate of TN was 83.6%, the average removal rate of COD was 90.39%, the sludge concentration was approximately 2100 mg·L-1, the sludge volume index was maintained below 50 mL·g-1, and the particle size was 700-800 nm. The EEM-PARAFAC model was used to characterize and analyze the EPS at different stages. The results revealed that changing the parameters could change the composition of EPS. The hydraulic residence time had a greater impact on the continuous flow system than the aeration intensity. In addition, a preliminary conceptual reaction process model in the anaerobic/aerobic alternating continuous flow system was built using high-throughput pyrosequencing and phylogenetic assignment. Eleven major functional bacteria related to nitrogen and phosphorus removal were found in the system.

Re-induction with modified CLAG regimen in relapsed or refractory acute myeloid leukemia in children bridging to allogeneic hematopoietic stem cell transplantation.

BACKGROUND: The prognosis for relapsed or refractory acute myeloid leukemia (RR-AML) in children is poor, and the preferred salvage chemotherapy is unclear. One regimen is cladribine, cytarabine, and granulocyte-colony stimulating factor (CLAG), but little is known about its efficacy and safety in children with RR-AML. METHODS: We enrolled RR-AML patients aged 0-18 years who received modified CLAG regimen for re-induction between July 1, 2015 and April 1, 2018, or conventional induction between August 1, 2011 and April 1, 2018. Patients were followed up to March 31, 2019. Patients underwent allogeneic stem cell transplantation (allo-SCT) or chemotherapy after the induction of complete remission (CR). The CR rate, survival, and side effects were analyzed. RESULTS: The CR rate for induction was 66.7% after one cycle and 75.0% after two cycles of the CLAG regimen in 12 children. The nine children who received conventional chemotherapy had a CR rate of 22.2% after one cycle and 33.3% after two cycles (P = 0.087 vs. CLAG). The 3-year event-free survival (EFS) of the CLAG group and the conventional treatment group were 44.4 ± 15.7% and 22.2 ± 13.8% (P = 0.112). The 3-year overall survival of the two groups were 59.5 ± 16.2% and 22.2% ± 13.8% (P = 0.057). The 3-year EFS for allo-SCT and chemotherapy after CLAG regimen was 66.7 ± 19.2% and 25.0 ± 21.7% (P = 0.015). A single case of chemotherapy-related death was recorded. CONCLUSION: Our data suggest a promising CR rate using CLAG salvage treatment in childhood RR-AML. Allo-SCT after CR may improve the long-term outcome in these patients.

HeLa-CCL2 cell heterogeneity studied by single-cell DNA and RNA sequencing.

The HeLa cells are the earliest and mostly used laboratory human cells for biomedical particularly cancer research. They were derived from a patient's cervical cancerous tissue, and are known for their heterogeneous cellular origin and variable genomic landscapes. Single-cell sequencing techniques with faithful linear and uniformly amplified genomes (DNA) and transcriptomes (RNA) may facilitate the study of cellular differences at the individual cell level. In this work, we have performed single-cell DNA and RNA sequencing with HeLa-CCL2 cells to study their heterogeneity. We have studied the complexity of copy number variations (CNVs) of HeLa-CCL2 genome at the single cell level, and revealed the transcriptomic heterogeneity of HeLa-CCL2. We also analyzed the relationship between genome and transcriptome at the single-cell level, and found overall correlation between CNV and transcriptome expression patterns. Finally, we concluded that although single-cell sequencing techniques are applicable to study heterogeneous cells such as HeLa-CCL2, the data analyses need to be more careful and well controlled.

Modulation of the Coordination Environment around the Magnetic Easy Axis Leads to Significant Magnetic Relaxations in a Series of 3d-4f Schiff Complexes.

A series of Salen-type Zn(II)-Dy(III) complexes [L1Zn(II)ClDy(III)(acac)2]·H2O (1), [L1Zn(II)BrDy(III)(acac)2]·H2O (2), [L1Zn(II)(H2O)Dy(III)(acac)2]·CH2Cl2·PF6 (3), [L2Zn(II)(H2O)Dy(III)(acac)2]·PF6 (4), and Co(III)-Dy(III) complexes [L1Co(III)Br2Dy(III)(acac)2]·CH2Cl2 (5), [L2Co(III)Cl2Dy(III)(acac)Cl(MeO)] (6), [L2Co(III)Cl2Dy(III)(acac)Cl(H2O)] (7), and [L2Co(III)Cl2Dy(III)(NO3)2(MeO)] (8) heterobinuclear single-molecule magnets (SMMs) were synthesized and magnetically characterized. These complexes were constructed by incorporating diamagnetic Zn(II) and Co(III) ions with acetylacetone (acac) and compartmental Schiff-base ligands (H2L1 = N, N'-bis(2-oxy-3-methoxybenzylidene)-1,2-phenylenediamine; H2L2 = N, N'-bis(2-oxy-3-methoxybenzylidene)-1,2-diaminocyclohexane). In the Zn(II)-Dy(III) (1-4) system, the coordination environments of the Dy(III) ions are nearly identical, but the apical coordination atom to the Zn(II) ion is different. Complexes 1, 2, and 4 displayed no magnetic relaxation in the absence of external magnetic field, but complex 3 displayed more pronounced SMM behavior with a relaxation energy barrier Ueff/ kB 38 K and magnetic hysteresis at 1.8 K. The SMM performances of 5, 6, and 7 were enhanced significantly by incorporating an octahedral Co(III) instead of square-pyramidal Zn(II) and replacing one of acac- group around Dy(III) ion by a neutral O atom, displaying Ueff of 167, 118, and 75 K as well as magnetic hysteresis up to 3.5 K. These studies indicated that the remote diamagnetic Zn(II) and Co(III) ions played a key role, and the SMM properties were very strongly related to the special coordination atoms configuration around Dy(III) ion. When this coordination configuration around was broken as 8 exhibited, however, it resulted in a dramatically decreased SMM performance. From this work, the key factors that significantly affect the SMM performance of these heteronuclear Zn(II)/Co(III)-Dy(III) SMMs are unambiguously presented.

Real-time polymerase chain reaction for diagnosing infectious mononucleosis in pediatric patients: A systematic review and meta-analysis.

In this meta-analysis, we evaluated the diagnostic role of Epstein-Barr virus deoxyribonucleic acid detection and quantitation in the serum of pediatric and young adult patients with infectious mononucleosis. The primary outcome of this meta-analysis was the sensitivity and specificity of Epstein-Barr virus (EBV) deoxyribonucleic acid (DNA) detection and quantitation using polymerase chain reaction (PCR). A systematic review and meta-analysis was performed by searching for articles that were published through September 24, 2014 in the following databases: Medline, Cochrane, EMBASE, and Google Scholar. The following keywords were used for the search: "Epstein-Barr virus," "infectious mononucleosis," "children/young adults/infant/pediatric," and "polymerase chain reaction or PCR." Three were included in this analysis. We found that for detection by PCR, the pooled sensitivity for detecting EBV DNA was 77% (95%CI, 66-86%) and the pooled specificity for was 98% (95%CI, 93-100%). Our findings indicate that this PCR-based assay has high specificity and good sensitivity for detecting of EBV DNA, indicating it may useful for identifying patients with infectious mononucleosis. This assay may also be helpful to identify young athletic patients or highly physically active pediatric patients who are at risk for a splenic rupture due to acute infectious mononucleosis.

[Clinical significance of sequential monitoring minimal residual disease in childhood B-cell acute lymphoblastic leukemia].

OBJECTIVE: To study the clinical significance of sequentially monitoring minimal residual disease (MRD) in childhood B-cell acute lymphoblastic leukemia (B-ALL). METHOD: Eighty one B-ALL cases were enrolled in the study from January 2004 to December 2009. Leukemia cell markers were detected by flow cytometry at diagnosis, then regularly followed-up. RESULTS: Of 81 cases, 80 achieved complete remission (CR) after induction therapy, 5-year event-free survival (EFS) was (76.80 ± 5.70)%. Among them, the EFS was (89.40 ± 5.90)% in standard risk group and (66.99 ± 13.60)% in intermediate risk group. Eight cases were screened for leukemia markers for MRD monitoring and identified in 68; and 5-year EFS was (79.10 ± 6.20)% and (62.50 ± 15.10)% (P > 0.05, respectively). MRD detection at day 35 in induction therapy showed that 52 of 68 cases were MRD negative (leukemia cells < 0.01%), the 5-year EFS being (88.50 ± 4.90)%, and 16 were MRD positive (leukemia cells ≥ 0.01%), the 5-year EFS being (42.10 ± 20.10)% (P > 0.05). Univariate analysis confirmed that there was a correlation between MRD monitoring and risk stratification. MRD detection at day 55 showed that among the 52 day 35 MRD negative cases, 51 were still negative, 1 positive, among 16 day 35 MRD positive cases, 14 (87.50%) turned negative, 2 still positive. Of the 68 cases, 9 were MRD positive within one year after CR (3 relapsed), 4 MRD positive after one year (2 relapsed) and 55 MRD negative (4 relapsed) (P > 0.05). CONCLUSIONS: Sequential monitoring MRD can find out treatment outcome and adjust therapy in time.

Evaluation of human MSCs cell cycle, viability and differentiation in micromass culture.

Mesenchymal stem cells (MSCs) have the potential to differentiate into distinct mesenchymal tissue cells. They are easy to expand while maintaining their undifferentiated state, which suggests that these cells could be an attractive cell source for tissue engineering of cartilage. In vitro high density micromass culture has been widely used for chondrogenesis induction. Our objective was to investigate human MSCs cell cycle, viability and differentiation in these conditions. Therefore, to induce human MSCs chondrogenesis, micromasses were cultured in the presence of transforming growth factor-beta1 in serum free medium for 21 days. Cell cycle, cell viability and cell phenotype were analyzed by flow cytometry. From day 0 to 7, the G0/G1 phase increased, whereas the S phase decreased gradually, but cell cycle phases (S, G0/G1 and G2/M) did not significantly change after day 7. Less than 10% of cells were apoptotic, but no necrosis was observed, even at day 21. We observed a decrease in CD90 and CD105 expression, from day 0 to 21. In conclusion, our results demonstrate a good viability of human MSCs in micromass culture during the whole period of culture. Moreover, micromass culture allowed human MSCs to be synchronized at the G0/G1 phase, while their phenotype suggested some degree of differentiation.

The effects of Chinese herb Angelica in focal cerebral ischemia injury in the rat.

This experiment was designed to study the therapeutic mechanisms of Angelica on the focal cerebral ischemia injury of the rat. The ischemic area was determined by TTC stain. And terminal deoxynucleotidyl transferase (TDT) mediated DUTP-biotin nick end labeling (TUNEL) method was applied to detect neuronal apoptosis. The expressions of Bcl-2 and Bax proteins were observed by immunohistochemical staining methods. Results show that the treatment with angelica reduced the volume of cerebral infarction (p < 0.05), and that the number of neuronal apoptosis cells decreased significantly (p < 0.01). Also the expression level of Bax protein decreased (p < 0.01). These results suggest that Angelica can reduce the number of apoptosis cells by decreasing the expression of Bax protein. This is maybe one of the mechanisms of the therapeutic effect of Angelica on focal cerebral ischemia injury.

[Effect of thyroid hormone on protein kinase C signal pathway in cardiac myocytes and fibroblasts of rats in vitro].

AIM: To study the effect of thyroid hormone on protein kinase C activity and isoprotein expressions in cardiac myocytes and fibroblasts of rats in vitro. METHODS: Cardiac myocytes and fibroblasts were cultured according to the method of Simpson. Cells were pretreated with 1% newborn calf serum (NCS) or Angiotensin II (Ang II) for 24 hours, then Triiodothyronine (T3) was added to the culture medium and the culture was kept for another 48 hours. The protein kinase C activation were measured by PepTaga non-radioactive PKC assay, and the expressions of PKC alpha and PKC epsilon were detected by Western blot method. RESULTS: At the condition of 1% NCS culture medium, T3 could inhibit PKC activity and PKC epsilon expression in cardiac myocytes significantly, but the expression of PKC alpha in cardiac myocytes was not influenced by T3. In cardiac fibroblasts, neither PKC activity nor PKC alpha and PKC epsilon expressions was influenced by T3. When cells were pretreated with Ang II for 24 hours, PKC activities in cardiac myocytes and fibroblasts were increased significantly, and PKC epsilon expressions in cardiac myocytes were also markedly increased. Following a T3 treatment, PKC activity and PKC epsilon expression in cardiac myocytes were markedly decreased, but PKC activity in cardiac fibroblasts was not changed. CONCLUSION: Whether at the condition of 1% NCS medium or in a pretreatment with Ang II, thyroid hormone could inhibit the PKC activity and PKC epsilon expression in cardiac myocytes. The influence of thyroid hormone on the PKC signal pathway in cardiac myocyte may be involved in many pathophysiological progress of myocardium.