Synthesis of 2,2-difunctionalized 2H-azirines via I2-mediated annulation of enamines.

Various 2,2-difunctionalized 2H-azirines were synthesized via I2-mediated annulation reactions of readily accessible enamines in the presence of nitrogen or non-nitrogen nucleophiles. The features of the present synthesis process also include no use of transition metals, simple operation, mild reaction conditions, a broad substrate scope, and gram-scale synthesis.

Urbanization promotes carbon storage or not? The evidence during the rapid process of China.

China's commitment to attaining carbon neutrality by 2060 has galvanized research into carbon sequestration, a critical approach for mitigating climate change. Despite the rapid urbanization observed since the turn of the millennium, a comprehensive analysis of how urbanization influences urban carbon storage throughout China remains elusive. Our investigation delves into the nuanced effects of urbanization on carbon storage, dissecting both the direct and indirect influences by considering urban-suburban gradients and varying degrees of urban intensity. We particularly scrutinize the roles of climatic and anthropogenic factors in mediating the indirect effects of urbanization on carbon storage. Our findings reveal that urbanization in China has precipitated a direct reduction in carbon storage by approximately 13.89 Tg of carbon (Tg C). Remarkably, urban sprawl has led to a diminution of vegetation carbon storage by 8.65 Tg C and a decrease in soil carbon storage by 5.24 Tg C, the latter resulting from the sequestration of impervious surfaces and the elimination of organic matter inputs following vegetation removal. Meanwhile, carbon storage in urban greenspaces has exhibited an increase of 6.90 Tg C and offsetting 49.70% of the carbon loss induced by direct urbanization effects. However, the indirect effects of urbanization predominantly diminish carbon storage in urban greenspaces by an average of 5.40%. The degree of urban vegetation management emerges as a pivotal factor influencing the indirect effects of urbanization on carbon storage. To bolster urban carbon storage, curbing urban sprawl and augmenting urban green spaces are imperative strategies. Insights from this study are instrumental in steering sustainable urban planning and advancing towards the goal of carbon neutrality.

[Study of the distribution of KIR3DL2 alleles among ethnic Han Chinese from Zhejiang].

OBJECTIVE: To study the distribution of KIR3DL2 alleles among ethnic Han Chinese from Zhejiang. METHODS: Genomic DNA was extracted by using a magnetic bead method. The full sequence of the KIR3DL2 gene was amplified with four pairs by PCR primers. The coding regions of 208 unrelated ethnic Han Chinese blood donors were analyzed using a BigDye Terminator v3.1 Sequencing Kit. The genotypes were assigned based on the nucleotide polymorphism of the KIR3DL2 gene. RESULTS: Among the 208 samples, 133 were KIR3DL2 heterozygotes and 75 were homozygotes. Forty six KIR3DL2 genotypes were detected. Respectively, 70, 33 and 23 individuals were found to have a KIR3DL2*00201/KIR3DL2*00201, KIR3DL2*00201/KIR3DL2*00701, and KIR3DL2*00201/KIR3DL2*01001 genotype. Twenty-two KIR3DL2 alleles were discovered, and the frequencies of KIR3DL2*00201, KIR3DL2*00701 and KIR3DL2*01001 were 57.45%, 13.46% and 9.13%, respectively. CONCLUSION: The distribution of KIR3DL2 alleles among ethnic Han Chinese in Zhejiang has been determined and fits the criteria for genetic polymorphism.

[Molecular characterization of a recombination allele of ABO blood group].

OBJECTIVE: To analyze the molecular characteristics of a recombinant allele of the ABO blood group. METHODS: The ABO phenotype was determined with the tube method. The coding regions of the ABO and FUT1 genes were analyzed by PCR-sequence based typing. The ABO alleles of the proband were determined by allele-specific primer sequencing. The full sequences of the ABO gene of the proband and her mother were determined through next generation sequencing. RESULTS: The red blood cells of the proband did not agglutinate with anti-H, and the sequence of the FUT1 gene was homozygous for c.551_552delAG.The proband was thereby assigned as para-Bombay. Bi-directional sequencing also found that she was heterozygous for c.261G/del,467C>T,c.526C>G,c.657C>T,c.703G>A,c.796C>A,c.803G>C and c.930G>A of the coding regions of the ABO gene. Allele-specific primer sequencing also found her to carry a ABO*A1.02 allele and a recombinant allele from ABO*O.01.01 and ABO*B.01. The recombination site was located between nucleotide c.375-269 and c.526, and the allele was maternally derived. CONCLUSION: An recombinant allele of the ABO gene has been identified, which has originated from recombination of ABO*O.01.01 with the ABO*B.01 allele.

Organocatalytic Asymmetric Michael Addition of Pyrazol-5-ones to ß-Trifluoromethyl-α,ß-unsaturated Ketones: Stereocontrolled Construction of Vicinal Quaternary and Tertiary Stereocenters.

An efficient organocatalytic asymmetric Michael addition of 4-substituted-pyrazol-5-ones to ß-trifluoromethyl-α,ß-unsaturated ketones was developed. In the presence of a dipeptide-based urea-amide tertiary amine catalyst, an array of chiral products containing pyrazolone and trifluoromethyl moieties bearing vicinal quaternary and tertiary stereocenters were obtained in good yields with good to excellent enantioselectivity and diastereoselectivity (up to 95% yields, up to 97% ee, and >20:1 d.r.). Moreover, the reaction was compatible with 4-substituted-pyrazol-5-ones containing either aryl or alkyl group at the C3 position.

Characterization of three new HLA Class I Alleles in Chinese individuals, HLA-B*46:68,-B*46:71,-B*46:72.

Three new HLA class I alleles were described in the Chinese population. HLA-B*46:68,-B*46:71,-B*46:72 alleles differ from HLA-B*46:01:01 by a single nucleotide substitution at position 485C>T, 484A>G, 299T>A respectively.

Eigenvalue decomposition and least squares algorithm for depth resolution of wavenumber-scanning interferometry.

Depth resolution of depth-resolved interferometry evaluated by Fourier transform is limited by the range of phase shifting. A novel algorithm, the eigenvalue decomposition and least squares algorithm (EDLSA), is proposed. Experimental results obtained using depth-resolved wavenumber-scanning interferometry demonstrate that the EDLSA performs better than the Fourier transform and complex number least squares algorithm. Not requiring any a priori information, the algorithm can replace the Fourier transform in depth-resolved interferometry with improved depth resolution.

[Establishment of a polymerase chain reaction sequencing based typing method for HLA-DPB1 exons 2 and 3 and investigation of their polymorphisms].

OBJECTIVE: To establish a polymerase chain reaction sequencing-based typing (PCR SBT) method for HLA-DPB1 exons 2 and 3, and to analyze their polymorphisms. METHODS: Based on the sequences of HLA-DPB1 loci, locus-specific primers were designed and applied to amplify the target sequences encompassing the entire exons 2 and 3 of HLA-DPB1. The amplification products were digested by enzymes and directly sequenced in both directions. The genotype was assigned by Assign 3.5+ SBT software. RESULTS: Specific target fragment was obtained with the PCR amplification, and good quality electropherogram was derived by direct sequencing. Among 242 individuals from Zhejiang Han population, 18 HLA-DPB1 alleles were detected. Alleles with a frequency of > 0.05 have included DPB1*05:01:01/135:01 (0.4112), DPB1*02:01:02 (0.1901), DPB1*04:01:01 (0.1136) and DPB1*02:02 (0.0620). A novel HLA-DPB1*168:01 allele has also been identified. Nine polymorphism sites were founded in the exon 3 region, which included a new SNP site 517 A>T. CONCLUSION: The PCR-SBT method for exons 2 and 3 of HLA-DPB1 is reliable, which allowed detection of polymorphisms in exon 3 of the HLA-DPB1 gene.

[Effect of α -1,2 fucosyltransferase gene 682A> G and 547_552delAG mutations on the activity of fucosyltransferase].

OBJECTIVE: To explore the effect of α -1,2 fucosyltransferase (FUT1) gene 682A> G and 547_552delAG mutations on the expression of FUT1 mRNA and activity of α -1,2 fucosyltransferase. METHODS: Recombinant expression vectors of FUT1 682A> G and FUT1 547_552delAG were constructed and transfected into COS-7 cells for stable expression screening. Expression of FUT1 mRNA was determined using real-time quantitative PCR. The activity of FUT1 was measured with high-performance liquid chromatography. RESULTS: Stably transfected COS-7 cells with wild type FUT1, FUT1 682A> G and FUT1 547_552delAG were respectively obtained. The FUT1 mRNA level of transfected cells with 682A> G and 547_552delAG recombination vectors have measured 101.69% and 102.79% compared with that of wild type FUT1 transfected cells. A specific protein band with about 46 kD was confirmed in the 682A> G transfected cell lysates by SDS-PAGE electrophoresis and Western blotting with 6× His Tag antibody. Similar protein was not identified in the 547_552delAG cells lysates. Enzymes activity of FUT1 682A> G has measured 61.01% compared with wild type FUT1 protein, whilst the activity of FUT1 547_557delAG was completely abolished. CONCLUSION: FUT1 682A> G and 547_552delAG mutations do not affect the transcript efficiency, although various mutations have different impact on the enzyme's activity.

[Development of a method for the separation of HLA-A, -B and -C haploid using biotinylated probe and streptavidin magnetic beads].

OBJECTIVE: To develop a method for separating the human leukocyte antigen (HLA)-A, -B and -C haploid using biotinylated probes and streptavidin magnetic beads in order to solve ambiguous HLA genotyping results. METHODS: Based on sequence information of HLA alleles from the IMGT/HLA database, the 5-biotinylated probes were designed. The probe was mixed and extended with corresponding genomic DNA, and incubated with streptavidin magnetic beads, which could form a streptavidin magnetic beads-biotin-probe DNA complex. The unique DNA haploid binding to corresponding probe was isolated after washes and elution. The separated haploid genomic DNA was used as template for HLA-A, -B and -C loci amplification and sequencing analysis. RESULTS: Among the 12 HLA-A probes, 19 HLA-B probes and 13 HLA-C probes, DNA sequencing has confirmed that 9 HLA-A probes, 9 HLA-B probes and 5 HLA-C probes could successfully separate the haploid from genomic DNA samples. CONCLUSION: The developed method for HLA-A, -B and -C haploid separation is reliable, which can solve certain ambiguity and improve the accuracy of HLA genotyping.

Full annotation of viral metagenomics in different components from Chinese blood donors using next-generation sequencing.

BACKGROUND: Emerging viruses in the blood of healthy/qualified donors can seriously affect transfusion safety. However, the virus characteristics in different healthy blood donors and blood components are still not fully understood. MATERIALS AND METHODS: Buffy coat (BC) and plasma specimens were collected from 32 whole blood donors, and platelet (PLT) and BC specimens from 30 apheresis platelet donors to explore the full annotation of viral metagenomics in different blood components from Chinese blood donors using next-generation sequencing technology. RESULTS: The study detected 56 viruses in the plasma and BC groups of whole blood donors. The plasma group had a significantly higher viral abundance and more types of viruses than the BC group. We detected 20 viruses in the PLT and BC groups of apheresis platelet donors. Viral abundance and types were significantly lower in the BC group than in the PLT group. According to ß-diversity analysis, the plasma group had a significantly different community structure and composition than the BC group. DISCUSSION: Viral nucleic acid is found in the blood of healthy Chinese blood donors, with the highest concentration in plasma, which could explain the distribution of viruses in the blood of healthy individuals.

Identification of the novel HLA-A*03:453 allele in a Chinese blood donor.

HLA-A*03:453 differs from HLA-A*03:02:01:01 by one single nucleotide substitution at position 376 G > A.

Identification of the novel HLA-DRB1*11:298 allele in a Chinese cord blood donor.

HLA-DRB1*11:298 shows one single nucleotide substitution at position 397 T>G compared with HLA-DRB1*11:01:01:01.

Identification of the novel HLA-A*29:171 allele by next-generation sequencing.

HLA-A*29:171 differs from HLA-A*29:01:01:01 by one nucleotide substitution at position 257T>G in exon 2.

The HLA-DRB1*12:92 and HLA-DRB1*12:101 alleles were identified by next-generation sequencing.

Compared with HLA-DRB1*12:02, the alleles HLA-DRB1*12:92 and HLA-DRB1*12:101 each show one nucleotide substitution respectively.

Shrub encroachment leads to accumulation of C, N, and P in grassland soils and alters C:N:P stoichiometry: A meta-analysis.

Soil stoichiometry of carbon (C), nitrogen (N), and phosphorus (P) are indicators for nutrient balance. Shrub encroachment into grasslands could change nutrient concentrations and stoichiometry in soils, but the general patterns remain unclear. With a meta-analysis of a global dataset covering 344 observations from 68 studies, we examined the responses of grassland soil C:N:P stoichiometry to shrub encroachment under various environmental conditions. Our results show that: 1) Shrub encroachment significantly increased the concentrations of soil C (+29 %), N (+25 %), P (+20 %), C:N (+5 %), C:P (+12 %), and N:P (+6 %). The magnitude of such effects varied with climate, soil texture, and soil layer. 2) Increases in SOC and TN concentrations mainly occurred in Mediterranean and very humid climate zones. Soil C:P and N:P decreased in semi-humid climate zone after shrub encroachment. 3) The increases in SOC and TN concentrations and in the C:N, C:P, and N:P ratios after shrub encroachment were greater in the topsoil than in deeper soil layers. 4) Both finest-textured soil (clay) and coarsest-textured soil (sand) are beneficial for increase of soil nutrient concentrations following shrub encroachment. 5) The magnitude of the change in soil C:N was negatively correlated with the duration of shrub encroachment, due to greater increases in soil TN than in SOC concentrations with longer durations of encroachment. Our results indicate that soil stoichiometric shifts in shrub-encroached grasslands are relatively sensitive to environmental factors, including soil texture, soil pH, and climate. These findings help us to better understand the effects of shrub encroachment on biogeochemical cycling, functioning, and services in grasslands across a broad range of spatio-temporal scales.

Distribution of MICB diversity in the Zhejiang Han population: PCR sequence-based typing for exons 2-6 and identification of five novel MICB alleles.

The polymorphism of major histocompatibility complex class I chain-related gene B (MICB) and variations in MICB alleles in a variety of populations have been characterized using several genotyping approaches. In the present study, a novel polymerase chain reaction sequence-based typing (PCR-SBT) method was established for the genotyping of MICB exons 2-6, and the allelic frequency of MICB in the Zhejiang Han population was investigated. Among 400 unrelated healthy Han individuals from Zhejiang Province, China, a total of 20 MICB alleles were identified, of which MICB*005:02:01, MICB*002:01:01, and MICB*004:01:01 were the most predominant alleles, with frequencies of 0.57375, 0.1225, and 0.08375, respectively. Nine MICB alleles were detected on only one occasion, giving a frequency of 0.00125. Of the 118 distinct MICB ∼ HLA-B haplotypes identified, 42 showed significant linkage disequilibrium (P < 0.05). Haplotypes MICB*005:02:01 ∼ B*46:01, MICB*005:02:01 ∼ B*40:01, and MICB*008 ∼ B*58:01 were the most common haplotypes, with frequencies of 0.0978, 0.0761, and 0.0616, respectively. Five novel alleles, MICB*005:07, MICB*005:08, MICB*027, MICB*028, and MICB*029 were identified. Compared with the MICB*005:02:01 sequence, a G > A substitution was observed at nucleotide position 210 in MICB*005:07, and a 1,134 T > C substitution in MICB*005:08 and an 862 G > A substitution in MICB*027 were detected. In addition, it appears that MICB*028 probably arose from MICB*004:01:01 with an A to G substitution at position 1,147 in exon 6. MICB*029 had a G > T transversion at nucleotide position 730 in exon 4, compared with that of MICB*002:01:01. On the basis of the new PCR-SBT assay, these observed results demonstrated MICB allelic variations in the Zhejiang Han population.

Description of the novel HLA allele, HLA-C*01:220 in a Chinese individual.

HLA-C*01:220 has one nucleotide change compared with HLA-C*01:02:01:01 in codon 163 of exon 3.

Description of two new HLA alleles, HLA-A*26:01:70 and HLA-A*26:01:74 in Chinese individuals.

Compared with HLA-A*26:01:01:01, the alleles HLA-A*26:01:70, and HLA-A*26:01:74 each show one nucleotide substitution, respectively.

Identification of the novel HLA-B*46:95N allele in a Chinese blood donor.

HLA-B*46:95N shows one nucleotide substitution at position 2 when compared with HLA-B*46:01:01:01.