Correlation of single nucleotide polymorphisms in the AGT gene with susceptibility to systemic lupus erythematosus in Northeast China.

To investigate the correlation between susceptibility to systemic lupus erythematosus (SLE) and single nucleotide polymorphisms (SNPs) rs699, rs4762 and rs1926723 in the AGT gene in the population of Northeast China, while also introducing a new method for early detection of SLE. A total of 856 cases of SLE patients and healthy volunteers who attended the First Affiliated Hospital of Harbin Medical University from January 2020 to December 2022 were recruited. Clinical information and biood samples were collected from particpants in this study. SNaPshot sequencing technology was used to sequence the bases of the rs699, rs4762 and rs1926723 in the AGT gene. The genetic stability of SNPs was analysed by means of Hardy-Weinberg (HWE) genetic equilibrium. The study examined the correlation between genetically stable SNPs and susceptibility to SLE using logistic regression analysis. Rs699 did not adhere to the principles of the HWE genetic equilibrium (p < .01). Conversely, both rs4762 and rs1926723 conformed to the HWE genetic equilibrium (p > .05). However, no significant differences in genotypes and alleles frequencies of the rs4762 were observed between the two groups (p > .05). Furthermore, there was a significant difference in the distribution of AG, GG genotypes frequency and G allele frequency at the rs1926723 between the two groups (p < .001). Individuals with AG and GG genotypes and the G allele had a significantly lower frequency of SLE, indicating a potential genetic protective factor against susceptibility to the SLE. The SNPs rs1926723 may be linked to the susceptibility to SLE, and the AG, GG genotypes and the G allele may be important protective factors for the development of SLE in Northeast China.

Enantioselective Total Synthesis of Spirotryprostatin A.

In this paper, we disclosed a novel enantioselective total synthesis of spirotryprostatin A (1) in 15 steps with a 7.4% total yield from commercially available 2-iodo-5-methoxyaniline and γ-butyrolactone. The key step features of this synthesis include the copper-catalyzed cascade reaction of o-iodoaniline derivatives with alkynone to introduce the quaternary carbon stereocenter and an aza-Michael tandem reaction to construct the spiro[pyrrolidine-3,3'-oxindole] moiety.

Labor agglomeration and urban air pollution: research on labor force based on skill heterogeneity in China.

Labor agglomeration with heterogeneous skills has different effects on urban air pollution. Based on the panel data of 263 prefecture level cities in China from 2006 to 2019, this paper constructs a Spatial Durbin Model to explore the impact of skill heterogeneous labor agglomeration and the interaction between skill heterogeneous labor agglomeration on urban air pollution. The results show that there is a positive U-shaped relationship between high-skilled labor agglomeration, low-skilled labor agglomeration, and urban air pollution. From the perspective of restraining urban air pollution, high-skilled labor agglomeration is stronger than low-skilled labor agglomeration. Under the influence of high skilled labor agglomeration, the inhibitory effect of low-skilled labor agglomeration on urban air pollution is enhanced. High-skilled labor agglomeration and low-skilled labor agglomeration reduce the degree of urban air pollution by promoting the improvement of urban innovation level. Based on this, this paper puts forward some policy suggestions, such as further promoting urban labor agglomeration, formulating reasonable urban population management policies, strengthening labor exchange and learning, and carrying out labor knowledge and skills training.

Visible light photocatalytic degradation of sulfanilamide enhanced by Mo doping of BiOBr nanoflowers.

Design of high-efficiency visible light photocatalysts is critical in the degradation of antibiotic pollutants in water, a key step towards environmental remediation. In the present study, Mo-doped BiOBr nanocomposites are prepared hydrothermally at different feed ratios, and display remarkable visible light photocatalytic activity towards the degradation of sulfanilamide, a common antibacterial drug. Among the series, the sample with 2% Mo dopants exhibits the best photocatalytic activity, with a performance 2.3 times better that of undoped BiOBr. This is attributed to Mo doping that narrows the band gap of BiOBr and enhances absorption in the visible region. Additional contributions arise from the unique materials morphology, where the highly exposed (102) crystal planes enrich the photocatalytic active sites, and facilitate the adsorption of sulfanilamide molecules and their eventual attack by free radicals. The reaction mechanism and pathways are then unraveled based on theoretical calculations of the Fukui index and liquid chromatography/mass spectrometry measurements of the reaction intermediates and products. Results from this study indicate that deliberate structural engineering based on heteroatom doping and morphological control may serve as an effective strategy in the design of highly active photocatalysts towards antibiotic degradation.

The electrochemical performance of reduced graphene oxide prepared from different types of natural graphites.

Graphene, as a new type of carbon material in the forefront of research, has been applied widely in the area of supercapacitors with the advantages of a large positive specific surface, high conductivity, stable chemical properties and good supercapacitor performance. In this study, an investigation on the electrochemical performance of reduced graphene oxides (rGOs) prepared from various natural graphites was conducted. X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, atomic force microscopy and electrochemical performance analysis were performed to characterize the as-prepared GOs and rGOs. The results demonstrated that a reduction modification of GO was necessary to optimize its electrochemical performance. The rGO has a great electrochemical performance with a good repair ability, better oxygen-containing functional group removal effect, lower structural defects, larger average size of the in-plane sp2 region and great specific capacitance.

[Research on sludge toxicity caused by DMF biodegradation and toxicity spatial distribution in sludge flocs].

The aerobic sequencing batch activated sludge system (SBR) was used to remove the toxic and refractory organic pollutant, N,N-dimethylformamide (DMF). The formation property and spatial distribution of the organic toxicity in sludge were studied. The operation parameters were controlled as follows: influent COD was about 300 mg x L(-1), every DMF concentration phase lasted 30 d(40 mg x L(-1), 80 mg x L(-1), 120 mg x L(-1)), the SBR cycle lasted 12 h, and DO was 2.0-3.0 mg x L(-1). The results showed that the sludge toxicity increased in the beginning and then decreased to a steady range at each DMF concentration phase; there was a positive correlation between the sludge toxicity and the initial DMF concentration; most of the sludge organic toxicity was caused by DMF biodegradation and existed in the inner extracellular polymeric substances (EPS) and intracellular section of sludge flocs.

[Effective nitrogen removal in low C/N wastewater with combined aerobic-low DO biofilm treatment process].

The municipal wastewater in China is characterized by low ratio of carbon to nitrogen, which is the key restrictive factor for effective biological removal of nitrogen. In this study, the aerobic-low DO biofilm process was used for the nitrogen removal of municipal wastewater. By means of adjusting inflow ratios of aerobic section to low-DO section, hydraulic retention time (HRT) and inflow ratio of carbon to nitrogen (C/N), the performances of nitrification in aerobic biofilm section and denitrification in low-DO section could be improved, the good performance of nitrogen removal was achieved. In order to insure the good effluent quality, especially for ammonia nitrogen and total nitrogen indexes, the nitrification and denitrification could be made up in aerobic and low-DO biofilm section respectively due to the coexistence of aerobic and anoxic zone in biofilm. There were 3 stages for the research process. In the first stage, the original C/N, inflow ratios of aerobic section to low-DO section were chosen as 3:1 and 1:1 respectively, then the effects of various HRT (aerobic section + low DO section) values such as (10 + 5) h, (8 + 4) h, (6 + 3) h, (4 + 2) h to nitrogen removal were analyzed. According to the conclusion in the first stage, the original C/N was kept at 3:1, HRT (aerobic section + low DO section) was (10 + 5) h. Then, the effects of various inflow ratios to nitrogen removal were studied in the second stage. In the third stage, when HRT(aerobic section + low DO section) was (10 + 5) h and inflow ratio was 1:1, the original C/N were adjusted from 2:1, 3:1, 5:1 to 10:1. To conclude, the optimal parameters for nitrogen removal in the biofilm system were as follows: original C/N = 5:1, inflow ratio of aerobic to low-DO section = 1:1, HRT of aerobic and low-DO sections were 10 h and 5 h respectively. As a result, COD, ammonia nitrogen and total nitrogen could be removed from 254 mg/L to 48 mg/L, 37.2 mg/L to 9.3 mg/L and 48.2 mg/L to 14.8 mg/L respectively.

[Rapid differentiation of human umbilical cord-derived mesenchymal stem cells into insulin-secreting cells under the sole induction of biological products].

In order to explore the feasibility of inducing the human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) to differentiate into insulin-secreting cells with biological products alone, hUC-MSCs were separated and purified from the whole umbilical cord by the sequent digestion of collagenase II and trypsin followed by two-step centrifugation. hUC-MSCs were induced with IMDM culture medium containing epidermal growth factor (EGF), basic fibroblast growth factor (bFGF) and Ginkgo biloba extract (GBE). Before and after the induction, the morphological changes were observed under inverse microscope; the islet-related genes were detected by RT-PCR; islet-like clusters (ILCs) were identified by dithizone (DTZ) staining; PDX-1 and immunoreactive insulin (IRI) were examined by immunofluorescence method; the quantity and quality of IRI secretion were assayed by chemiluminescence immunoassay and Western blot respectively. The results showed that the purified hUC-MSCs presented long spindle-like shape and parallel or spiral arrangement which are typical morphological features of MSCs. After the induction, hUC-MSCs changed gradually into round or oval shape and gathered together to form ILCs; there were more than one hundred clusters on the growth surface of a flask of T25; ILCs were stained into positive mauve by DTZ and positive for PDX-1 and IRI; Western blot displayed that most of the IRI was proinsulin (PI). Therefore, hUC-MSCs can rapidly differentiate into insulin-secreting cells under the sole induction of EGF, bFGF, GBE and IMDM, but ILCs are not mature enough to produce sufficient true insulin.