[Investigation of ABO allelic competition phenomena in a pedigree with Bw11 subtype].

OBJECTIVE: To investigate the serological and molecular characteristics of a pedigree carrying an allele for ABO*BW.11 blood subgroup. METHODS: The ABO blood type of 9 pedigree members were determined by serological methods. Exons 6 and 7 of the ABO gene were amplified by PCR and directly sequenced. The patient and her father were also subjected to clone sequencing analysis. RESULTS: Serological tests demonstrated that the proband and her younger brother had an ABw subtype, whilst her father and two daughters had Bw subtype. Clone sequencing found that the exon 7 of the ABO gene of the proband had a T>C substitution at position 695, which was identified as a BW.11 allele compared with the reference sequence B.01. This BW.11 allele was also identified in the proband's father, brother and two daughters. Due to allelic competition, the A/BW.11 and BW.11/O alleles demonstrated significantly different phenotypes. CONCLUSION: The c.695T>C substitution of the ABO gene may lead to allelic competition in the Bw11 subtype. Combined molecular and serological methods is helpful for precise blood grouping.

[Identification of a Bw14 subtype and exploration for its molecular basis].

OBJECTIVE: To identify a rare subtype of the ABO blood group system and explore its molecular basis. METHODS: Based on a standard serological assay, ABO subtype and haplotype were analyzed through PCR amplification of the 7 exons and adjacent introns of the ABO gene and TA clone sequencing. RESULTS: Forward typing showed a B type, while reverse typing demonstrated an extremely weak anti-B on routine gel analysis, which indicated a forward and reverse typing discrepancy. Absorption-elution testing confirmed that there was no A antigen on the surface of patient's red blood cells. Sequencing of the ABO gene showed a G>A exchange at position 523 in exon 7, which resulted in a Val to Met substitution at codon 175. Clone sequencing of the amplificons of the ABO gene showed an ABO* Bw14/O01 heterozygote genotype. CONCLUSION: Molecular method is useful for the identification of ambiguous blood groups. A 523G>A substitution of the ABO gene resulting in a Bw14 subtype probably underlies the weak B phenotype noted in the patient.

Genotype frequency of human neutrophil antigen-3 polymorphisms in the Yi, Han, and Tibetan populations of China.

BACKGROUND: Human neutrophil antigen-3 (HNA-3) alloantibodies can cause fatal transfusion-related acute lung injury (TRALI). Most frequencies of SLC44A2 alleles encoding the HNA-3a/b antigens have been established in Han individuals by polymerase chain reaction with sequence-specific priming (PCR-SSP). We sequenced SLC44A2 gene fragments and determined allele frequencies in three ethnicities of China. STUDY DESIGN AND METHODS: Genomic DNA was extracted from 448 samples of 100 blood donors of Yi ethnicity in Xichang, Liangshan; 248 Han in Nanjing, Jiangsu; and 100 Tibetan in Lhasa, Tibet. A PCR-SSP was applied to determine the phase of two single-nucleotide polymorphisms (SNPs); SLC44A2 haplotypes were constructed. RESULTS: In the 567 nucleotides of the SLC44A2 gene covered by our sequencing approach in Han individuals, we detected the known 331-44G>A (rs12972963) and 461G>A (rs2288904) polymorphisms. In the 243 nucleotides sequenced in Yi and Tibetan populations, we detected the known 461G>A and 503-15T>C (rs1560711) polymorphisms. A PCR-SSP for the common HNA-3a/b SNP was 100% concordant. The frequencies of the HNA-3a allele were 0.58, 0.66, and 0.69 in Yi, Han (Nanjing), and Tibetan, respectively (0.42, 0.34, and 0.31 for HNA-3b). CONCLUSIONS: The Yi population of China had the highest frequency of blood donors at risk of harboring anti-HNA-3a compared to any population studied so far. We confirmed that the underlying SLC44A2*2 allele is more common in China than in any European or African populations.

[Molecular mechanisms underlying DEL phenotype among ethnic Han individuals from Jiangsu].

OBJECTIVE: To explore the molecular mechanism underlying the DEL phenotype among RhD negative ethnic Han individuals from Jiangsu, China. METHODS: The DEL phenotype was determined by an adsorption elution test among 57 RhD negative blood donors. The Rh C, c, E, and e phenotypes were detected by a tube method. PCR with sequence-specific primering (PCR-SSP) assay was used to determine the RHCE genotypes. The RHD gene of the DEL individuals were amplified with polymerase chain reaction and subjected to Sanger sequencing analysis. RESULTS: Among the 57 RhD negative donors, 10 (17.54%) were determined as having the DEL phenotype. The major RhCE phenotypes for DEL and RhD negative cases were RhCcee (80.0%) and Rhccee (61.7%), respectively. All RHD gene sequences of the 10 individuals have harbored a G>A mutation at position 1227 of exon 9. CONCLUSION: A proportion of RhD negative individuals determined by routine serological method are actually DEL with RHD gene mutations. RHD *1227A is the most prevalent DEL genotype among ethnic Han Chinese from Jiangsu. Further research on the phenotype and underlying molecular mechanism of DEL is important for blood transfusion.

[MAX-DOAS Tomography Reconstruction for Gas Plume].

In order to achieve precisely two-dimensional spatial distribution reconstruction of smoke plume, passive MAX-DOAS tomography is established, the measurement of the spatial distribution of the exhaust plume is implemented by more passive multi-axis differential absorption spectrum system. First, the multi-axis differential absorption spectrum system and its mechanism of inverse gas concentration are introduced in the paper. Then, algebra iterative algorithm is adopted to extract the information of the trace gas concentration in reconstruction simulation with different models and different scanning optical path, and the reconstruction program is designed. Then, the numerical simulation results are compared. Finally, a platform of multi-axis differential absorption optical tomography system is set up, a field campaign was carried out. The numerical simulation results show that the MAX-DOAS tomography can accurately reconstruct two-dimensional spatial distribution of plume model, the re- construction error of MAX-DOAS tomography with four light sources is about a third of the reconstruction error with double light sources, moreover, the reconstruction time is about a quarter of the reconstruction time of double light sources, and the reconstruction error of the twin peaks model is greater than that of the one peak model. Field test results show that the integral data of reconstruction image is consistent with the measured projection data of multi-axis differential absorption spectrum, the spatial distribution reconstruction of plume is in line with the actual situation. Studies have shown that the result of numerical simulation and field test results have consistency.

Molecular genetic analysis and structure model of a rare B(A)02 subgroup of the ABO blood group system.

BACKGROUND: Serological analysis of ABO blood group has been widely applied in transfusion medicine. However, ABO subgroups with different expression of blood group antigens sometimes cannot be determined by serological methods. Therefore, genotyping is useful to understand the variant ABO phenotypes. MATERIAL AND METHODS: Exon 6 to exon 7 and adjacent introns of the ABO gene from a donor with ABO typing discrepancy were amplified and sequenced. Cloning sequencing was also performed to identify the allele. To explore the effect of mutation, three dimensional model of mutant p.Pro234Ala was built and optimized. RESULTS: The variant B (c. 700C > G) allele expressed an AweakB phenotype with anti-A in his serum with a ABO*B(A)02/O02 heterozygote genotype. Cloning sequencing confirmed that the c.700C > G single nucleotide polymorphism was associated with a B101 allele. Three dimensional molecular modeling suggested that p.Pro234Ala might affect the conformation of His233, Met266 and Ala268, which were known as critical residues for donor recognition. CONCLUSION: ABO genotyping is needed for correct identification subgroups to improve accuracy evaluation of blood typing and increase the safety of blood transfusion. Alteration of DNA sequence in the ABO gene resulted in amino acid substitutions and led to a weak or missing expression of ABO antigens.

Chemically bonded CdS/Bi2MoO6 Z-scheme heterojunction synergises with strong internal electric field for photocatalytic CO2 reduction.

Constructing strong interfacial electric fields to enhance the surface charge transport kinetics is an effective strategy for promoting CO2 conversion. Herein, we present the fabrication of CdS-Bi2MoO6 Z-scheme heterojunctions with a robust internal electric field (IEF) using an in situ growth technique, establishing chemical bonding between the components. The IEF at the interface can offer an impetus for the segregation and transportation of photogenerated carriers, while the Cd-O chemical bonding mode acts as a rapid conduit for these carriers, thereby reducing the charge transfer distance. As a result, the Z-scheme charge transfer is accelerated due to the synergistic influence of these two factors. Therefore, the optimized CdS/Bi2MoO6 Z-scheme heterojunction possesses significantly enhanced dynamic carrier mobility, thus promoting the conversion of CO2 to CO without the need for additional co-catalysts or sacrificial agents. This optimization yields a remarkable CO selectivity of up to 97%. Meanwhile, the expedited Z-scheme charge transfer mechanism is validated through X-ray photoelectron spectroscopy, Kelvin probe force microscopy, and in situ diffuse reflectance infrared Fourier transform spectroscopy.

Unraveling Synergistic Effect of Defects and Piezoelectric Field in Breakthrough Piezo-Photocatalytic N2 Reduction.

Piezo-photocatalysis is a frontier technology for converting mechanical and solar energies into crucial chemical substances and has emerged as a promising and sustainable strategy for N2 fixation. Here, for the first time, defects and piezoelectric field are synergized to achieve unprecedented piezo-photocatalytic nitrogen reduction reaction (NRR) activity and their collaborative catalytic mechanism is unraveled over BaTiO3 with tunable oxygen vacancies (OVs). The introduced OVs change the local dipole state to strengthen the piezoelectric polarization of BaTiO3 , resulting in a more efficient separation of photogenerated carrier. Ti3+ sites adjacent to OVs promote N2 chemisorption and activation through d-π back-donation with the help of the unpaired d-orbital electron. Furthermore, a piezoelectric polarization field could modulate the electronic structure of Ti3+ to facilitate the activation and dissociation of N2 , thereby substantially reducing the reaction barrier of the rate-limiting step. Benefitting from the synergistic reinforcement mechanism and optimized surface dynamics processes, an exceptional piezo-photocatalytic NH3 evolution rate of 106.7 µmol g-1  h-1 is delivered by BaTiO3 with moderate OVs, far surpassing that of previously reported piezocatalysts/piezo-photocatalysts. New perspectives are provided here for the rational design of an efficient piezo-photocatalytic system for the NRR.

Circulating endothelial cells and tumor blood volume as predictors in lung cancer.

The current criteria for evaluating antiangiogenic efficacy is insufficient as tumor shrinkage occurs after blood perfusion decreases. Tumor blood volume (BV) in computed tomography perfusion imaging and circulating endothelial cells (CEC) might predict the status of angiogenesis. The present study aimed to validate their representation as feasible predictors in non-small-cell lung carcinoma (NSCLC). A total of 74 patients was categorized randomly into two arms undergoing regimens of vinorelbine and cisplatin (Navelbine and platinum [NP]) with rh-endostatin or single NP. The response rate, perfusion imaging indexes and activated CEC (aCEC) during treatment were recorded. Progression-free survival (PFS) was determined through follow up. Correlations among the above indicators, response and PFS were analyzed: aCEC increased significantly in cases of progressive disease after single NP chemotherapy (P = 0.024). Tumor BV decreased significantly in cases with a clinical benefit in the combined arm (P = 0.026), whereas inverse correlations existed between ∆aCEC (post-therapeutic value minus the pre-therapeutic value) and PFS (P = 0.005) and between ∆BV and PFS (P = 0.044); a positive correlation existed between ∆aCEC and ∆BV. Therefore, both aCEC and tumor BV can serve as predictors, and detection of both indicators can help evaluate the chemo-antiangiogenic efficacy in NSCLC more accurately.

[Feasibility of volume perfusion CT (VPCT) imaging in antiangiogenic treatment of rabbit VX2 soft-tissue tumor].

OBJECTIVE: To explore the feasibility of volume perfusion CT imaging to dynamically monitor and evaluate the response of rabbit VX2 soft-tissue tumor to antiangiogenic treatment. METHODS: To establish an experimental animal model of VX2 soft tissue tumor on 20 New Zealand white rabbits. Twenty rabbits were randomly divided into 2 groups. The therapy group was treated with recombinant human endostatin (3 mg·kg⁻¹·d⁻¹) for 7 days, and the control group received saline in the same dose only. Four times of CT volume perfusion scan were performed before treatment and on the second, forth, seventh days of treatment, respectively. The value of blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability (PMB) in the VX2 tumors were measured after scanning. The microvessel density (MVD) and expression of vascular endothelial growth factor (VEGF) in the tumors were determined using immunohistochemical staining. RESULTS: The tumor volume of the therapy group was (1.36 ± 0.73) cm³ on the forth day of treatment and (1.69 ± 0.68) cm³ on the seventh day of the treatment. The tumor volume of the control group was (2.35 ± 0.62) cm³ on the fourth day of treatment and (3.87 ± 0.93) cm³ on the seventh day of the treatment (P < 0.05). On the seventh day of treatment, tumor necrosis ratio of the therapy group and the control group was (25.58 ± 5.51)% and (42.93 ± 4.34)%, respectively (P < 0.05). Comparing the perfusion parameters between the two groups on the same day, and the second, forth, seventh days of treatment, the value of PMB of the therapy group was (70.36 ± 23.46) ml·100 ml⁻¹·min⁻¹, (79.64 ± 13.68) ml·100 ml⁻¹·min⁻¹ and (84.76 ± 3.55) ml·100 ml⁻¹·min⁻¹, respectively, and that in the control group was (26.61 ± 6.47) ml·100 ml⁻¹·min⁻¹, (33.74 ± 16.47) ml·100 ml⁻¹·min⁻¹ and (30.47 ± 10.64) ml·100 ml⁻¹·min⁻¹, respectively (P < 0.05). The value of BF in the therapy group and control group was (71.19 ± 12.21) ml·100 ml⁻¹·min⁻¹ and (43.56 ± 12.21) ml·100 ml⁻¹·min⁻¹, respectively, on the seventh day of treatment (P < 0.05). The parameters on different days in the same group were compared. In the control group, the value of BF on the seventh day of treatment was significantly lower than that before and on the second and forth days of treatment (P < 0.05). However, in the therapy group, the value of PMB on the second, forth, and seventh days of treatment was significantly higher than that before treatment (P < 0.05). MVD of tumor in the control group was increased gradually, whereas increased on the first day and then decreased more in the therapy group. The VEGF expressions did not differ significantly between the experimental and control groups. CONCLUSIONS: Volume perfusion CT is helpful to quantify the tumor perfusion and evaluate the functional changes of tumor vasculature, and then evaluate the early therapeutic effect of antiangiogenic treatment.

A novel evidence combination method based on stochastic approach for link-structure analysis algorithm and Lance-Williams distance.

In response to the traditional Dempster-Shafer (D-S) combination rule that cannot handle highly conflicting evidence, an evidence combination method based on the stochastic approach for link-structure analysis (SALSA) algorithm combined with Lance-Williams distance is proposed. Firstly, the degree of conflict between evidences is calculated based on the number of correlation coefficients between evidences. Then, the evidences with a number of correlation coefficients greater than the average number of correlation coefficients of evidence are connected to construct an evidence association network. The authority weight of the evidence is calculated based on the number of citations in the concept of SALSA algorithm combined with the support of the evidence. Subsequently, the Lance-Williams distance between the evidences is calculated and transformed into support of the evidence. Next, the authority weight and support of evidence are combined to jointly construct a novel correction coefficient to correct the evidence. Finally, the corrected evidence is fused using the D-S combination rule to obtain the final fusion result. The numerical results verify that the method proposed in this paper can effectively solve the problem of the traditional D-S combination rule being unable to handle highly conflicting evidence.

Response of Aboveground Net Primary Production, Species and Phylogenetic Diversity to Warming and Increased Precipitation in an Alpine Meadow.

The uncertain responses of aboveground net primary productivity (ANPP) and plant diversity to climate warming and increased precipitation will limit our ability to predict changes in vegetation productivity and plant diversity under future climate change and further constrain our ability to protect biodiversity and ecosystems. A long-term experiment was conducted to explore the responses of ANPP, plant species, phylogenetic α-diversity, and community composition to warming and increased precipitation in an alpine meadow of the Northern Tibet from 2014 to 2019. Coverage, height, and species name were obtained by conventional community investigation methods, and ANPP was obtained using observed height and coverage. Open-top chambers with two different heights were used to simulate low- and high-level climate warming. The low- and high-level increased precipitation treatments were achieved by using two kinds of surface area funnel devices. The high-level warming reduced sedge ANPP (ANPPsedge) by 62.81%, species richness (SR) by 21.05%, Shannon by 13.06%, and phylogenetic diversity (PD) by 14.48%, but increased forb ANPP (ANPPforb) by 56.65% and mean nearest taxon distance (MNTD) by 33.88%. Species richness, Shannon, and PD of the high-level warming were 19.64%, 9.67%, and 14.66% lower than those of the low-level warming, respectively. The high-level warming-induced dissimilarity magnitudes of species and phylogenetic composition were greater than those caused by low-level warming. The low- rather than high-level increased precipitation altered species and phylogenetic composition. There were significant inter-annual variations of ANPP, plant species, phylogenetic α-diversity and community composition. Therefore, climate warming and increased precipitation had non-linear effects on ANPP and plant diversity, which were due to non-linear changes in temperature, water availability, and/or soil nutrition caused by warming and increased precipitation. The inter-annual variations of ANPP and plant diversity were stronger than the effects of warming and especially increased precipitation on ANPP and plant diversity. In terms of plant diversity conservation and related policy formulation, we should pay more attention to regions with greater warming, at least for the northern Tibet grasslands. Besides paying attention to the responses of ANPP and plant diversity to climate change, the large inter-annual changes of ANPP and plant diversity should be given great attention because the large inter-annual variation indicates the low temporal stability of ANPP and plant diversity and thus produces great uncertainty for the development of animal husbandry.

Effects of Short-Term Nitrogen Addition on Soil Fungal Community Increase with Nitrogen Addition Rate in an Alpine Steppe at the Source of Brahmaputra.

The soil fungal community plays a crucial role in terrestrial decomposition and biogeochemical cycles. However, the responses of the soil fungal community to short-term nitrogen addition and its related dominant drivers still remain unclear. To address this gap, we conducted an experiment to explore how different levels of nitrogen addition (five levels: 0, 2.5, 5, 10, and 20 g N m-2 y-1) affected the soil fungal community in an alpine steppe at the source of Brahmaputra. Results showed that the reduced magnitudes of soil fungal species and phylogenetic α-diversity increased with the increasing nitrogen addition rate. Nitrogen addition significantly changed the community composition of species, and the dissimilarity of the soil fungal community increased with the increasing nitrogen addition rate, with a greater dissimilarity observed in the superficial soil (0-10 cm) compared to the subsurface soil (10-20 cm). Increases in the soil nitrogen availability were found to be the predominant factor in controlling the changes in the soil fungal community with the nitrogen addition gradient. Therefore, short-term nitrogen addition can still cause obvious changes in the soil fungal community in the alpine grassland at the source of Brahmaputra. We should not underestimate the potential influence of future nitrogen deposition on the soil fungal community in the high-altitude grassland of the Qinghai-Tibet Plateau. Adverse effects on the soil fungal community should be carefully considered when nitrogen fertilizer is used for ecosystem restoration of the alpine grassland of the Qinghai-Tibet Plateau.

Hydrochemical characteristics of surface waters and their relationships to the Kashin-Beck Disease in Longzi County, Tibet.

Although previous studies have been reported between the Kashin-Beck Disease (KBD) epidemic and the hydrochemical characteristics of surface waters, the etiology of the disease remains unclear. In the present study, we comprehensively investigated the relationship between the KBD and the hydrochemical characteristics of surface waters in Longzi County. Results show that, the pH (mean = 7.27 ± 0.30), total hardness (TH, mean = 57.08 ± 45.74 mg L-1), total dissolved solids (TDS, mean = 67.56 ± 44.00 mg L-1) and oxidation-reduction potential (ORP, mean = 84.11 ± 23.55 mV) of surface waters in KBD endemic areas are lower than those in the non-KBD endemic areas (means of pH = 7.49 ± 0.30; TH = 262.06 ± 123.29 mg L-1; TDS = 253.25 ± 100.39 mg L-1; ORP = 215.90 ± 55.99 mV). These results suggest that long-term consumption of low TDS, essential trace elements (e.g., nickel, cobalt, iron, selenium, zinc, molybdenum, and iodine) deficient, and potential toxic elements (e.g., arsenic) enriched waters by humans likely causes the KBD. Environmental factors such as the geology and geomorphology may produce biogeochemical imbalance, geomorphic, vegetation types and local climatic conditions may have significant impact on food fungi toxin poisoning and water organic compound poisoning, and these also impact the KBD occurrence.

[Identification of Weak D Type 1 in Rh Blood Group System and Discussion of Transfusion Strategy].

OBJECTIVE: To investigate the molecular mechanism of one patient with abnormal serological phenotype in RhD and discuss the transfusion strategy. METHODS: The RhD variant sample was screened from a patient with IgM type anti-D antibody and further determined by three different sources of anti-D antibodies. Ten exons and the adjacent introns of the RHD gene were amplified, purified and sequenced. RhCE phenotypes and RHCE genotypes were detected. RESULTS: The patient with Rh variant showed abnormal results of serological tests. The RHD gene sequence analysis showed that the RHD*01W.01 with a variation (c.809T>G, p.Val270Gly) in exon 6 of the RHD gene was found in the patient. The RhCE phenotype was CcEe. The genotyping results of RHCE were consistent with the serological typing results. CONCLUSION: The Rh variant of the patient is RHD*01W.01, these findings indicate that RhD variants should be analyzed by molecular assays for the sake of safe transfusion.

[Differences of drought tolerance of the main tree species in Dongling Mountain, Beijing, China as indicated by tree rings]. / æ ‘æœ¨å¹´è½®æ­ç¤ºçš„ä¸œçµå±±ä¸»è¦æ ‘ç§é—´å¹²æ—±è€å—æ€§å·®å¼‚.

Forests in Beijing exhibit vulnerability to increasing stress of extreme drought in recent years. To investigate the drought tolerance of different tree species, we chose three tree species (Larix principis-rupprechtii, Pinus tabuliformis, and Quercus wutaishanica) from the forest of Dongling Mountain in Beijing and used dendroecological method to analyze the relationship between radial growth and climate, as well as their resistance and resilience to extreme drought events. Our results showed that the radial growth of L. principis-rupprechtii and P. tabuliformis was significantly negatively correlated with monthly mean temperature from May to June, but that of Q. wutaishanica was significantly negatively correlated with monthly mean temperature only in May. The radial growth of L. principis-rupprechtii was significantly positively correlated with monthly mean precipitation in June, monthly mean relative humidity from May to June and August to September. The radial growth of P. tabuliformis was significantly positively correlated with monthly mean precipitation and monthly mean relative humidity from June to August. The radial growth of Q. wutaishanica was significantly positively correlated with monthly mean precipitation in February and May, and monthly mean relative humidity in May. The radial growth of all the three species was significantly positively correlated with monthly mean SPEI (standardized precipitation evapotranspiration index) from May to July. L. principis-rupprechtii was least drought tolerant, as indicated by the greatest growth reduction (46.6%-69.6%), lowest resistance (0.534, 0.304, 0.530) and resilience (0.686, 0.570, 0.753) during the three extreme drought events occurred in the 1994, 2001-2002, and 2007. In contrast, tree growth of Q. wutaishanica showed the highest drought resistance in 2007, whereas no significant differences were observed between other two species. Extreme drought events caused by continuous high temperature and reduced precipitation during the growing season accounted for the reduction in tree radial growth. The various physiological and ecological strategies of tree species were the possible reasons for the difference in drought tolerance. Our results could provide a basis for the selection of suitable afforestation tree species and the formulation of forest protection mea-sures to maintain forest ecosystem functions and services under the background of undergoing climate change.