Detection and exposure assessment of pesticide residues in leek in He’nan Province

ObjectiveTo evaluate the health risk of pesticide exposure from leek， the pesticide residue in leek from Henan market was investigated.MethodsThe residues of 16 pesticides in leek sold on Henan market in 2020 were detected and analyzed. According to health guidance values such as food consumption data of the World Health Organization， acute reference dose formulated by Joint Meeting on Pesticide Residues and adaptable daily intake in “National food safety standard-Maximum residue limits for pesticides in food”， the acute and chronic exposure risks of pesticide residues in leek were evaluated by point assessment method， and the cumulative exposure was evaluated by hazard index method.ResultsThere were many types of pesticide residues in leek samples and 93.81% （424/452） of the samples were positive. 7 of the 14 pesticides exceeded their MRLs， and the violation rate of all samples was 16.15%. The detection of multiple pesticides was relatively serious， and 56.42% of the samples contained more than two pesticide residues. In the acute exposure assessment， the acute risks of carbofuran， procymidone and phorate exceeded the acceptable level. In the chronic exposure assessment， the chronic risk of omethoate exceeded the acceptable level. And insecticide pesticides had cumulative poisoning risk.ConclusionThe situation of pesticide residues in leek in Henan province was relatively prominent. To ensure the safety of agricultural products， it was recommended that the routine monitoring and use of pesticide， especially high-risk pesticides such as omethoate， carbofuran， procymidone and phorate should be strengthened

Gecko CD59 Is Implicated in Proximodistal Identity during Tail Regeneration

Several adult reptiles, such as Gekko japonicus, have the ability to precisely re-create a missing tail after amputation. To ascertain the associated acquisition of positional information from blastemal cells and the underlying molecular mechanism of tail regeneration, a candidate molecule CD59 was isolated from gecko. CD59 transcripts displayed a graded expression in the adult gecko spinal cord with the highest level in the anterior segment, with a stable expression along the normal tail. After tail amputation, CD59 transcripts in the spinal cord proximal to the injury sites increased markedly at 1 day and 2 weeks; whereas in the regenerating blastema, strong CD59 positive signals were detected in the blastemal cells anterior to the blastema, with a gradual decrease along the proximodistal (PD) axis. When treated with RA following amputation, CD59 transcripts in the blastema were up-regulated. PD confrontation assays revealed that the proximal blastema engulfed the distal one after in vitro culture, and rabbit-anti human CD59 antibody was able to block this PD engulfment. Overexpression of the CD59 during tail regeneration causes distal blastemal cells to translocate to a more proximal location. Our results suggest that position identity is not restricted to amphibian limb regeneration, but has already been established in tail blastema of reptiles. The CD59, a cell surface molecule, acted as a determinant of proximal–distal cell identity

Chemokine (C-C Motif) Ligand 2 (CCL2) in Sera of Patients with Type 1 Diabetes and Diabetic Complications

Chemokine (C-C motif) ligand 2 (CCL2), commonly known as monocyte chemoattractant protein-1 (MCP-1), has been implicated in the pathogenesis of many diseases characterized by monocytic infiltration. However, limited data have been reported on MCP-1 in type 1 diabetes (T1D) and the findings are inconclusive and inconsistent.In this study, MCP-1 was measured in the sera from 2,472 T1D patients and 2,654 healthy controls using a Luminex assay. The rs1024611 SNP in the promoter region of MCP-1 was genotyped for a subset of subjects (1764 T1D patients and 1323 controls) using the TaqMan-assay.Subject age, sex or genotypes of MCP-1 rs1024611SNP did not have a major impact on serum MCP-1 levels in either healthy controls or patients. While hemoglobin A1c levels did not have a major influence on serum MCP-1 levels, the mean serum MCP-1 levels are significantly higher in patients with multiple complications (mean = 242 ng/ml) compared to patients without any complications (mean = 201 ng/ml) (p = 3.5×10(-6)). Furthermore, mean serum MCP-1 is higher in controls (mean = 261 ng/ml) than T1D patients (mean = 208 ng/ml) (p<10(-23)). More importantly, the frequency of subjects with extremely high levels (>99(th) percentile of patients or 955 ng/ml) of serum MCP-1 is significantly lower in the T1D group compared to the control group (odds ratio = 0.11, p<10(-33)).MCP-1 may have a dual role in T1D and its complications. While very high levels of serum MCP-1 may be protective against the development of T1D, complications are associated with higher serum MCP-1 levels within the T1D group

The Four Patterns of the East Branch of the Kuroshio Bifurcation in the Luzon Strait

Based on the self-organizing map (SOM) method, a suite of satellite measurement data, and Hybrid Coordinate Ocean Model (HYCOM) reanalysis data, the east branch of the Kuroshio bifurcation is found to have four coherent patterns associated with mesoscale eddies in the Pacific Ocean: anomalous southward, anomalous eastward, anomalous northward, and anomalous westward. The robust clockwise cycle of the four patterns causes significant intraseasonal variation of 62.2 days for the east branch. Furthermore, the study shows that the four patterns of the east branch of the Kuroshio bifurcation can influence the horizontal and vertical distribution of local sea temperature

Comprehensive Evaluation of University Safety Culture Construction Level Based on &ldquo;2&ndash;4&rdquo; Model

Based on the &ldquo;2&ndash;4&rdquo; model of accident causation, a comprehensive index system of the safety culture construction level in colleges and universities is set up. This system consists of 4 primary indicators and 28 secondary indicators. Taking a university as an example, applying the analytic hierarchy process and fuzzy comprehensive evaluation method, this study establishes a comprehensive evaluation model to evaluate the construction level of the university&rsquo;s safety culture. The results show that the construction level of the university&rsquo;s safety culture is consistent with the actual situation. This study provides useful insights and feasible paths for promoting the safety and stability of colleges and universities and building a higher level of safety on campus

A Small Surge in Incidence of SARS-CoV-2 Omicron Variant in the “Dynamic Zero” Period

To describe the epidemiological characteristics and transmission dynamics of SARS-CoV-2 Omicron variant during “Dynamic Zero” period, we analyzed data on the 108 laboratory-confirmed SARS-CoV-2 cases during 14 to 30 May 2022 in Beichen district, Tianjin, China. We collected information on demographic characteristics, exposure history, and illness timelines of the 108 cases. We described characteristics of the patients and estimated the key epidemiological parameters, including serial interval and the time-dependent reproduction number of the Omicron variant, Rt. Among the 108 laboratory-confirmed patients, the median age was 38 years old, and 50.9% were females. Obvious symptoms were observed among 67.6% (73/108) of all cases, and major clinical manifestations included fever, sore throat, and cough, which occurred in 31.5%, 26.9%, and 19.4% of the 108 cases, respectively. The mean and standard deviation of the SI were estimated as 2.89 and 0.95 days, the Rt varied from 1.24 to 0.27 for a 7-day timelapse. The low reproduction number and the Omicron outbreak being suppressed within a short time marked the effectiveness of the implemented public health measures, such as nucleic acid screening, social distancing, masking, vaccination, medical treatment of patients, and isolation of close contacts. These measures play an important role in fulfilling the goal of controlling the spread of the disease

Nonmonotonic Self-Deformation of Cell Nuclei on Topological Surfaces with Micropillar Array

Cells respond to the mechanical signals from their surroundings and integrate physiochemical signals to initiate intricate mechanochemical processes. While many studies indicate that topological features of biomaterials impact cellular behaviors profoundly, little research has focused on the nuclear response to a mechanical force generated by a topological surface. Here, we fabricated a polymeric micropillar array with an appropriate dimension to induce a severe self-deformation of cell nuclei and investigated how the nuclear shape changed over time. Intriguingly, the nuclei of mesenchymal stem cells (MSCs) on the poly­(lactide-<i>co</i>-glycolide) (PLGA) micropillars exhibited a significant initial deformation followed by a partial recovery, which led to an “overshoot” phenomenon. The treatment of cytochalasin D suppressed the recovery of nuclei, which indicated the involvement of actin cytoskeleton in regulating the recovery at the second stage of nuclear deformation. Additionally, we found that MSCs exhibited different overshoot extents from their differentiated lineage, osteoblasts. These findings enrich the understanding of the role of the cell nucleus in mechanotransduction. As the first quantitative report on nonmonotonic kinetic process of self-deformation of a cell organelle on biomaterials with unique topological surfaces, this study sheds new insight into cell–biomaterial interactions