Search

ObjectiveTo understand the contamination status of Campylobacter in meat products of Baotou， the pathogenic characteristics such as drug resistance genes， antibiotic sensitivities， molecular typing were analyzed.MethodsThree hundred meat products were collected from 2019 to 2022， which were cultured for Campylobacter isolation. Sensitivities to antibiotics， drug resistance genes and mutation sites of isolated Campylobacter were detected and genetic characteristics were analyzed by pulsed field gel electrophoresis （PFGE） method as well.ResultsA total of 142 Campylobacter were isolated from 300 meat products， of which the isolation rate of raw poultry was 65.71% （138/210）. The detection rate of Campylobacter coli was significantly higher than that of Campylobacter jejuni （χ2=12.48， P

Pancreatic cystic tumors (PCN) refer to cystic tumor lesions originating from the epithelium and/or interstitial tissue of the pancreatic duct. PCN can be roughly divided into mucinous tumors and non-mucinous tumors. The former mainly includes intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN), while the latter mainly includes serous cystic neoplasms (SCN) and solid-pseudopapillary neoplasms (SPN) and cystic neuroendocrine neoplasms (cNET). Different types of PCNs have differentiated biological behaviors, and some types of PCNs have a risk of developing a malignancy. Preoperative identification of PCN malignancy on CT and MRI imaging is of great significance. Malignant indications for MCN are surgical indications， such as a diameter greater than or equal to 4 cm. IPMN accounts for 22% of PCN, and the risk of malignancy in main pancreatic duct type and mixed type IPMN can reach up to 70.9% and 76.5%, while the risk of malignancy in branch pancreatic duct type IPMN is 2.8%-10.7%. High risk signs of malignancy for IPMN include enhanced parenchymal or diameter of parietal nodules ≥ 5 mm, main pancreatic duct dilation (≥ 10 mm), and obstructive jaundice, and surgical treatment is recommended for these patients. SCN is more common in middle-aged and elderly women, with a male to female ratio of 1:3. Serous cystadenocarcinoma is rare, accounting for only 0.1% of pancreatic SCN. The 2015 edition of the Diagnosis and Treatment Guidelines for Pancreatic Cystic Diseases recommends that all SPNs patients should undergo surgical treatment. When the tumor of SPN with incomplete capsule, the mass diameter larger than 6 cm, and the tumor located in the tail of the pancreas, may have a higher ability of invasiveness and distant metastasis. cNET accounts for approximately 7% of PCN. Imaging diagnosis should be combined with medical history and lesion components, etc. The diagnostic point for SPN on image is that MCN is a round, thick walled cystic tumor that almost exclusively occurs in females in the body and tail of the pancreas body, often presenting as an “intracystic cyst”. IPMN is more common in elderly men. The main pancreatic duct type of IPMN presents as diffuse or segmental dilation of the main pancreatic duct, excluding obstructive factors. Branch pancreatic duct type of IPMN usually presents as tubular cystic tumors that communicate with the pancreatic duct, while mixed type of IPMN combines both manifestations. SCN is a lobulated, thin-walled oligocystic or multicystic honeycomb tumor. SPN is a larger round cystic solid tumor that is more common in young women. cNET is a cystic solid tumor with significantly enhanced circular or crescent shaped edges. There is significant controversy in domestic and foreign guidelines regarding the selection of indications for PCN surgery, and pancreatic surgery is difficult with many postoperative complications, posing challenges to the standardized treatment of PCN. Identifying the imaging characteristics of PCN and clarifying imaging diagnosis has clinical significance.

Alternaria mycotoxins are the secondary metabolites of Alternaria species, which have obvious toxicity （mutagenicity, teratogenicity and carcinogenicity, etc） to humans and animals. Alternariol （AOH）, alternariol monomethyl ether （AME）, alternuene （ALT）, tenuazonic acid （TeA） and tenoxin （TEN） are the most studied at present. Alternaria mycotoxins was reported in apples, orange, tomatoes, corns and other agricultural products. Eating these foods contaminated by Alternaria mycotoxins will cause serious harm to human health. In this paper, the pollution status and the detection technology of Alternaria mycotoxins were summarized, and the future research direction of Alternaria mycotoxins was prospected. The purpose was to provide references for the risk assessment, detection and prevention of Alternaria mycotoxins in foods.

Autosomal recessive congenital ichthyosis caused by CERS3 mutations is extremely rare in clinical practice. We recently identified a family of autosomal recessive congenital ichthyosis and performed multigene exome sequencing for hereditary skin diseases to identify causative genes. Mutation analysis revealed compound heterozygous mutations of c.746A>G(from the mother) and exon12 deletion(from the father)in CERS3 were detected in the proband, which were verified by Sanger sequencing and co-segregated with the ichthyosis phenotype in the proband and her parents. These mutations were both reported for the first time. For the treatment, the proband received an oral acitretin capsules of 20 mg once daily. After 3-month follow up, the patient's lesion improved significantly.

At present, the maximum predictable time of tropical cyclone using numerical model is limited to 2 weeks. Statistical forecasting methods have substantial advantages in mining the potential value of massive meteorological and oceanographic observations, surpassing the limit of numerical forecast, and providing a new way to solve the bottlenecks of tropical cyclone forecasts. A novel statistical prediction scheme is proposed for tropical cyclone annual frequency and genesis location in the Northwest Pacific. The effect of large-scale meteorological factors including sea surface temperature, the geopotential height, the humidity, the vorticity, the wind shear, the Nio3.4 index, the QBO index and the SO index on the annual frequency of tropical cyclone in Northwest Pacific are considered. Correlations between the annual frequency of tropical cyclone and the large-scale environmental variables are analyzed and 14 highly correlated predictors are selected to predict tropical cyclone frequency. The least absolute shrinkage and selection operator method is used to select 8 factors from 14 initial predictors. Then, a prediction model based on random forest is established using training samples (1979-2015) for calibration and testing samples (2016-2020) for validation. In addition, the impact of environmental conditions including the vorticity, the wind shear, the humidity, the potential intensity, the sea surface temperature anomaly and the Nio3.4 index on the formation location of tropical cyclone is also investigated. The stepwise regression algorithm is used to choose a set of independent predictive variables by an automatic procedure. The local Poisson regression is performed on training datasets using count data inside data circles whose size is determined by the method of likelihood cross validation maximation. The seasonality of tropical cyclone genesis location is added to Poisson model. Results show that the random forest model presents a major variation and trend of tropical cyclone annual frequency though there are some deviations from the fitted data. The rank importance of influence indicates the primary effect of sea surface temperature and secondary effect of atmospheric variables on tropical cyclone frequency, which further reveals the applicability of the random forest model. The local Poisson regression model predicts where the tropical cyclone is most likely to occur. This model performs well when tropical cyclone occurs in the region of the Philippine and has some deviation in some months when tropical cyclone occurs in the region of the South China Sea. This model has good performance in predicting tropical cyclone genesis location but is weak in predicting abnormal situations. Finally, these two models are used to simulate tropical cyclone genesis activity in 1979-2020. The distribution of simulated tropical cyclone genesis points is consistent with the observations. This new prediction scheme can provide support for tropical cyclone risk analysis.

The 2NaBH4+MgH2 and 2NaBH4+MgH2+0.1MFx (M＝Ni, Ti, Zr;x＝2, 3, 4) hydrogen storage composites were prepared by ball milling. The morphology, element distribution, and crystal structure of the composites were detected by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD), respectively. In addition, the hydrogen release thermodynamic properties of the materials were tested by differential scanning calorimetry (DSC) and temperature-programmed desorption (TPD). The results show that the peak temperature of the first hydrogen release process for 2NaBH4+MgH2 is decreased by 8.9, 35.7 ℃ and 54.5 ℃ by the addition of NiF2, TiF3 and ZrF4, respectively. In addition, the NaMgF3 phase that appeared during the hydrogen release process changes the reaction path of the first hydrogen release process, and catalyzes the second hydrogen release process of 2NaBH4+MgH2, which reduces the peak temperature of the second dehydrogenation process by 18.0 ℃, 31.1 ℃ and 34.1 ℃, respectively. The quantity ratio of hydrogen release for 2NaBH4+MgH2 reaches 91.7%, 91.9% and 98.7% by the addition of NiF2, TiF3 and ZrF4, respectively. In these three catalysts, ZrF4 shows the best catalytic effect on the entire hydrogen release process of 2NaBH4+MgH2. Therefore, 2NaBH4+MgH2+0.1ZrF4can be used as a potential application system of fuel cell hydrogen supply system.

Objective: It was the method of evaluating regional food safety status through food safety evaluation index model. Methods: In the index model, various factors affecting food safety, such as the size of the city, the types of food, the hazards of the test items, the place of production, etc., were comprehensively considered, and a variety of data sources were used to support the model. Using this model, the results of food safety index could be calculated from multiple angles and different levels, such as region, food category, region and food category. Results: Sampling data of Guangxi food safety assessment in 2021 had been utilized for empirical research. The classic large sample estimation method and empirical Bayesian estimation method had been applied for model calculation. It was found that the results from these two methods had a certain differences, but both methods got the same results showing that restaurant and catering food safety was significantly poorer than other food categories. In addition, the Bayesian estimation method could effectively solve the calculation problem when the pass rate was 100% or the values were largely close. Conclusion: The model could calculate the food safety index results from multiple angles and different levels, such as regions, food types.

To provide experimental evidence that defines the safety limits of electromagnetic exposure, the effects of long-term and low-dose electromagnetic irradiation during the developmental stage of free-move behaving Sprague Dawley (SD) rats on their learning and cognitive abilities were investigated. A 1.8 GHz electromagnetic wave was used as the irradiation source, and the absorbed dose was set at 0.40 W/kg during the 8-hour working time and 0.08 W/kg during the rest time of the day, the whole irradiation was continuously administered for 4 weeks. The water maze experiment was performed to detect the learning and memory ability of the rats. The chemical colorimetric method was used to measure the level of cholinergic markers, the level of monoamine neurotransmitters, the activity of antioxidant enzymes, and the concentration of oxidative stress products in the hippocampus of the rats. In addition, the hippocampal tissue was sectioned, stained, and observed under an optical microscope. The results showed that the hippocampal tissue in the brain of the exposed group was not significantly different from that of the sham group, but the content of cholinesterase was reduced and the content of acetylcholine and the activity of acetylcholine transferase were increased in the exposed group. The contents of the neurotransmitter dopamine and serotonin (5-HT) were also significantly higher in the exposed group than those in the sham group. The water maze test results showed that there was no significant change in the behavior of rats in the exposed group. Although long-term and low-dose electromagnetic radiation can cause disorders of the cholinergic system and neurotransmitter levels in SD rats, the changes in these indicators did not cause a decline in the learning and memory ability of rats, and the levels of cholinergic system markers and neurotransmitters returned to normal after 14 days.

Postpartum fatigue is an important issue that threatens women’s health. The incidence of postpartum fatigue is high. Failure to intervene in time may lead to adverse outcomes such as postpartum depression, premature termination of breastfeeding, child abuse, and low infant development. This article reviews the concepts, characteristics, related factors, adverse effects, and interventions of postpartum fatigue. The aim is to improve doctors’ and nurses’ awareness of on postpartum fatigue in pregnant women, enrich the research content and methods, stimulate the interest of nurses, and actively carry out targeted intervention research to prevent or reduce the occurrence of adverse outcomes.

Transcription-blocking lesions (TBLs) stall elongating RNA polymerase II (Pol II), which then initiates transcription-coupled repair (TCR) to remove TBLs and allow transcription recovery. In the absence of TCR, eviction of lesion-stalled Pol II is required for alternative pathways to address the damage, but the mechanism is unclear. Using Protein-Associated DNA Damage Sequencing (PADD-seq), this study reveals that the p97-proteasome pathway can evict lesion-stalled Pol II independently of repair. Both TCR and repair-independent eviction require CSA and ubiquitination. However, p97 is dispensable for TCR and Pol II eviction in TCR-proficient cells, highlighting repairs prioritization over repair-independent eviction. Moreover, ubiquitination of RPB1-K1268 is important for both pathways, with USP7s deubiquitinase activity promoting TCR without abolishing repair-independent Pol II release. In summary, this study elucidates the fate of lesion-stalled Pol II, and may shed light on the molecular basis of genetic diseases caused by the defects of TCR genes.

To study the impact of acid environment on the water-rich filling materials, experimental methods including intensity detection, scanning electron microscopy and X-ray diffraction were used to analyze the macro and micro changes of water-rich filling materials in acid environment and to discuss the corrosion and deterioration mechanism. After soaking for 180 d in hydrochloric solu-tions of pH 1 and pH 3, the compressive strength of the materials decreases by 88.8% and 58%, respectively, compared with that of standard curing for 28 d. After soaking in a sulfuric acid solution of pH 3, the compressive strength decreases by 68%. When the ma-terials were soaked in a sulfuric acid solution of pH 1, the compressive strength is zero. Microscopic tests show that dihydrate gypsum is generated in the materials with the prolongation of immersion time in the sulfuric acid solution. In the hydrochloric acid solution, di-hydrate gypsum is produced only in the solution of pH 1 after soaking for 180 d. The corrosion of the hydrochloric acid solution on the materials is mainly the dissolution corrosion of hardened structure with the neutralization effect of H+. The corrosion of the sulfuric acid solution on the materials is the dissolution corrosion of hardened structure with the neutralization effect of H+ and the expansion corrosion of dihydrate gypsum. The corrosive action of the sulfuric acid solution on the materials is stronger than that of the hydrochlo-ric acid solution.

As for the problem that different gypsum types have different influence on the condensation performance of water-rich filling materials,micro experiments,such as X-ray diffraction,scanning electron microscopy and infrared spectroscopy,were used to analyze the composition of the hardened body and investigate the influence of dihydrate gypsum and hemihydrate gypsum on the setting and hardening characteristics of water-rich filling materials. It is found that in a water-rich filling material system of sulphoaluminate cement-gypsum-lime,the gypsum type should be dihydrate gypsum so as to ensure the normal condensation setting and hardening; if hemihydrate gypsum is used as a raw material,the water-rich filling material has not strength after hydrating for 7 d. When dihydrate gypsum is adequate,the generated ettringite crystals are fine needle-like; but when dihydrate gypsum is inadequate,the generated ettringite crystals are short hexagonal columnar. The strength of the water-rich filling material is mainly derived from ettringite generated by the reaction of sulphoaluminate cement gypsum and lime,rather than the hydration products of cement generated by itself such as hydration calcium sulphoaluminate,alumina gel and calcium hydroxide.

In order to research the impact of carbonate ions on water-rich filling materials,strength testing,scanning electron microscopy,X-ray diffraction analysis and IR spectrum testing were used to analyze the macro- and micro-structural change and the corrosion and deterioration mechanism of the materials in sodium carbonate solutions. It is found that the compressive strength of the materials in a sodium carbonate solution whose mass fraction is 10% decreases significantly with increasing soaking time. When the soak age is 90 d,the compressive strength of the materials decreases by 72.5% compared with standard curing for 28 d. After soaking for 28 d the specimen surface is muddy. XRD patterns show that after soaking in a sodium carbonate solution whose mass fraction is 10%,thaumasite generates in the materials. With increasing soaking time the amount of thaumasite increases. Infrared spectroscopy results show that there does not exist[AlO6]. This confirms that ettringite in the materials soaking in the sodium carbonate solution drastically reduces and transforms into pulpy thaumasite. As non-cemented materials,thaumasite will cause serious damage to the hardening body of the materials. This shows that the carbonate solution has corrosive action on water-rich filling materials.

Niche-derived growth factors support self-renewal of mouse spermatogonial stem and progenitor cells through ERK MAPK signaling and other pathways. At the same time, dysregulated growth factor-dependent signaling has been associated with loss of stem cell activity and aberrant differentiation. We hypothesized that growth factor signaling through the ERK MAPK pathway in spermatogonial stem cells is tightly regulated within a narrow range through distinct intracellular negative feedback regulators. Evaluation of candidate extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK)-responsive genes known to dampen downstream signaling revealed robust induction of specific negative feedback regulators, including Spry4, in cultured mouse spermatogonial stem cells in response to glial cell line-derived neurotrophic factor or fibroblast growth factor 2. Undifferentiated spermatogonia in vivo exhibited high levels of Spry4 mRNA. Quantitative single-cell analysis of ERK MAPK signaling in spermatogonial stem cell cultures revealed both dynamic signaling patterns in response to growth factors and disruption of such effects when Spry4 was ablated, due to dysregulation of ERK MAPK downstream of RAS. Whereas negative feedback regulator expression decreased during differentiation, loss of Spry4 shifted cell fate toward early differentiation with concomitant loss of stem cell activity. Finally, a mouse Spry4 reporter line revealed that the adult spermatogonial stem cell population in vivo is demarcated by strong Spry4 promoter activity. Collectively, our data suggest that negative feedback-dependent regulation of ERK MAPK is critical for preservation of spermatogonial stem cell fate within the mammalian testis.