[Investigation and analysis of occupational hazard factors in different industries in Tongliao City].

Objective: To investigate the occupational hazard factors of different industries in Tongliao City, and to provide scientific basis for the prevention and control of occupational disease in Tongliao City. Methods: In July 2021, the detection data of coal dust, silica dust, cement dust, benzene, noise and other occupational hazard factors, as well as the occupational health examination data of workers in various positions of 104 enterprises in different industries in Tongliao City were cllected and anylazed. χ(2) test was used to analyze the results of chest radiography of workers in different age groups. Results: A total of 104 enterprises were investigated, and the median time-weighted average concentration (C(TWA)) of coal dust, silic a dust, cement dust and benzene in contact with test posts were 0.94, 0.30, 0.70 and 0.95 mg/m(3), respectively. The median 8 h equivalent sound level (L(EX, 8 h)) of noise was 74.1 dB (A) . The over standard rates of silica dust, cement dust and noise contact positions were 10.83% (16/240) , 7.14% (2/28) and 0.48% (3/628) , respectively. The differences of chest X-ray examination of coal dust and silica dust workers in different working ages were statistically significant (χ(2)=218.50, 531.80, P<0.001) . The difference of hearing threshold of noise workers with different working age was statistically significant (χ(2)=1290.00, P<0.001) . The rates of leukopenia and neutropenia were 41.90% (44/105) and 20.95% (22/105) in benzene exposed workers. The positive rate of brucella exposure workers was 1.33% (1/75) for tiger red plate agglutination test and 3.23% (3/93) for tube agglutination test. Conclusion: Silica dust, cement dust and noise exceed the standard in some posts and places in the Tongliao City, and some workers are infected with Brucella. In the future, we can focus on monitoring noise-generating posts, strengthen supervision and implement prevention and control measures to reduce the incidence of occupational diseases.

[The role of Keap1/Nrf2/HO-1 signal pathway in liver injury induced by rare earth neodymium oxide in mice].

Objective: To investigate the role of Keap1/Nrf2/HO-1 signaling pathway in liver injury induced by neodymium oxide (Nd(2)O(3)) in mice. Methods: In March 2021, forty-eight SPF grade healthy male C57BL/6J mice were randomly divided into control group (0.9% NaCl), low dose group (62.5 mg/ml Nd(2)O(3)), medium dose group (125.0 mg/ml Nd(2)O(3)), and high dose group (250.0 mg/ml Nd(2)O(3)), each group consisted of 12 animals. The infected groups were treated with Nd(2)O(3) suspension by non-exposed tracheal drip and were killed 35 days after dust exposure. The liver weight of each group was weighed and the organ coefficient was calculated. The content of Nd(3+) in liver tissue was detected by inductively coupled plasma mass spectrometry (ICP-MS). HE staining and immunofluorescence was used to observe the changes of inflammation and nuclear entry. The mRNA expression levels of Keap1, Nrf2 and HO-1 in mice liver tissue were detected by qRT-PCR. Western blotting was used to detect the protein expression levels of Keap1 and HO-1. The contents of catalase (CAT), glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) were detected by colorimetric method. The contents of interleukin 1ß (IL-1ß), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were determined by ELISA. The data was expressed in Mean±SD. Two-independent sample t-test was used for inter-group comparison, and one-way analysis of variance was used for multi-group comparison. Results: Compared with the control group, the liver organ coefficient of mice in medium and high dose groups were increased, and the Nd(3+) accumulation in liver of mice in all dose groups were significantly increased (P<0.05). Pathology showed that the structure of liver lobules in the high dose group was slightly disordered, the liver cells showed balloon-like lesions, the arrangement of liver cell cords was disordered, and the inflammatory exudation was obvious. Compared with the control group, the levels of IL-1ß and IL-6 in liver tissue of mice in all dose groups were increased, and the levels of TNF-α in liver tissue of mice in high dose group were increased (P<0.05). Compared with the control group, the mRNA and protein expression levels of Keap1 in high dose group were significantly decreased, while the mRNA expression level of Nrf2, the mRNA and protein expression levels of HO-1 were significantly increased (P<0.05), and Nrf2 was successfully activated into the nucleus. Compared with the control group, the activities of CAT, GSH-Px and T-SOD in high dose group were significantly decreased (P<0.05) . Conclusion: A large amount of Nd(2)O(3) accumulates in the liver of male mice, which may lead to oxidative stress and inflammatory response through activation of Keap1/Nrf2/HO-1 signal pathway. It is suggested that Keap1/Nrf2/HO-1 signal pathway may be one of the mechanisms of Nd(2)O(3) expose-induced liver injury in mice.

[Research progress on the regulatory mechanism of non-coding RNA in arsenic toxicity].

Arsenic is a non-metallic element, and the International Agency for Research on Cancer has identified arsenic and its compounds as carcinogens. Arsenic and its compounds can be absorbed through the respiratory tract, skin and digestive tract, distributed in the liver, kidney, lung and skin, and cause damage. Non-coding RNAs are closely related to arsenic-induced nervous system disorders, cell necrosis, reproductive toxicity, and carcinogenesis. In recent years, the network regulation of microRNAs (miRNAs) , long non-coding RNAs (lncRNAs) , and circular RNAs (circRNAs) among non-coding RNAs in various diseases induced by arsenic has become a new research field. This paper summarizes the existing scientific research results, and expounds the mechanism of miRNAs, lncRNAs and circRNAs in arsenic toxicity, and provides basic data and theoretical basis for the prevention and treatment of arsenic poisoning.

[Effects of Nd(2)O(3) exposure of rare earth particles on C57 BL/6J male mice sex hormone secretion and CYP11A1/PLZF/STRA8 protein expression].

Objective: To explore the effects of Nd(2)O(3) exposure to rare earth particles on the secretion of sex hormones, cytochrome P450 family member 11A1 (CYP11A1) , spermatogenesis markers promyelocytic leukemia zinc finger protein (PLZF) and retinoic acid stimulating gene 8 (STRA8) protein in C57 BL/6J male mice. Methods: In March 2021, Forty-eight male C57 BL/6J mice aged 6-8 weeks divided into control group and Nd(2)O(3) exposure low, medium and high dose groups (exposing doses of 62.5, 125.0, 250.0 mg/ml Nd(2)O(3)) , 12 per group. The mice in the Nd(2)O(3) groups were perfused with different doses of Nd(2)O(3) suspension by a one-time non-exposing tracheal instillation method, and the control group was perfused with an equal volume of normal saline, with a volume of 0.1 ml, to establish a mouse reproductive function injury model. After 28 days of exposure, the mice's body weight, testes and epididymis were weighed, and the organ coefficients were calculated; the two epididymis were taken to make a sperm suspension to determine the sperm count, survival rate, and deformity rate; inductively coupled plasma mass spectrometry (ICP-MS) method was used to detect the content of Nd in mouse testis tissue; HE staining was used to detect testicular tissue pathological changes and quantitative analysis; enzyme-linked immunosorbent assay (ELISA) method was used to detect serum luteinizing hormone (LH) and follicle stimulating hormone (FSH) and testosterone (T) content; western blot was used to detect the protein levels of CYP11A1, PLZF and STRA8 in testicular tissues. Results: Compared with the control group, with the increase of the exposure dose, the Nd content in the testis of the mice showed an increasing trend, the sperm survival rate and LH showed a decreasing trend, and the sperm deformity rate showed an increasing trend (P<0.05) ; Pathological showed that the number of sperm in the seminiferous tubules of the testicular tissue in the Nd(2)O(3) medium and high dose groups was significantly reduced, and the germinal epithelial disintegration, intraepithelial vacuolization, and exfoliation of spermatogenic cells and supporting cells occurred; The height of germinal epithelium was significantly reduced, and the percentage of damaged seminiferous tubules showed an increasing trend (P<0.05) ; FSH and T levels in serum in the middle and high dose groups of Nd(2)O(3), and CYP11A1, PLZF and STRA8 proteins in testicular tissues showed a downward trend with increasing dose (P<0.05) . Conclusion: The rare earth particulate Nd(2)O(3) may interfere with the expression of CYP11A1, PLZF and STRA8 protein, thereby causing the disorder of sex hormone secretion in the body, the maintenance of spermatogonia and the obstruction of the process of meiosis, causing reproductive function damage.

[Clinical characteristics of silent pheochromocytoma].

Objective: To summarize the clinical characteristics of silent paraganglioma. Methods: A total of 247 pheochromocytoma cases in Peking University First Hospital between January 1993 and December 2015 were analyzed retrospectively.The cases were divided into two groups according to whether they had hypertension: non-silent group (193 cases) and silent group (53 cases), then the clinical characteristics between the groups were compared, and the clinical features of silent pheochromocytoma were reviewed. Results: There were 53 silent pheochromocytoma cases in this study, which accounted for 21.5% (53/247), and imaging was the main way to find the tumor. Forty-one in 53 cases (77.4%) located in adrenal gland, in which 31 cases (75.6%) were benign and 2.3-8.0 cm in diameter, while 10 cases (24.4%) were malignant and 3.5-12.0 cm in diameter. Twelve in 53 cases (22.6%) located in extra-adrenal tissue, in which 4 cases were benign and 2.0-5.5 cm in diameter, while 8 cases were malignant and 5.0-10.5 cm in diameter. With the tumor diameter increased, the malignant rate increased: 1 in 8 cases in diameter<3 cm, 2 in 12 cases in diameter 3-5 cm, 15 in 33 cases in diameter>5 cm were malignant. There was no significant difference in age, sex, tumor location, benign or malignant rate between the two groups (all P>0.05). Compared with the non-silent group, the proportion of tumor size≥5 cm in silent group was significantly higher (62.3% vs 45.9%, P=0.034), and the incidence of hyperglycemia and the concentrations of norepinephrine and epinephrine were lower (all P<0.05) in silent group.Misdiagnosis was common in silent group, and up to 35.8% (19/53) had not been diagnosed correctly before operation. Twenty-one in 53 (39.6%) silent pheochromocytoma cases occured severe intra-operative blood pressure fluctuation. Conclusions: Silent pheochromocytoma was not uncommon and imaging was the main way to find it. The tumor size was always big and misdiagnosis was common, especially extra-adrenal tumors. Therefore, regardless of the adrenal or extra-adrenal tumors, especially in diameter>3.0 cm but with normal blood pressure, the possibility of silent pheochromocytoma should be considered. In order to reduce misdiagnosis and intra-operative blood pressure fluctuations, preoperative diagnosis and preparation, as well as intra-operative monitoring should be fully made.

[Analysis of clinical characteristics of paraganglioma in 42 patients].

Objective: To summarize the clinical characteristics of paraganglioma. Methods: A total of 215 pheochromocytoma/ paraganglioma cases in Peking University First Hospital between January 1996 and December 2014 were retrospectively analyzed. The patients were divided into two groups according to the tumor position: pheochromacytoma group (173 patients) and paraganglioma group (42 patients). Then the clinical characteristics between the groups were compared. Results: There were 42 paraganglioma cases in the study, accounting for 19.5%. The most common position was retroperitoneum (66.7%, 28/42), followed by bladder (19.0%, 8/42), para-aorta (11.9%, 5/42) and pelvic cavity (2.4%, 1/42). Sixty-nine percent (29/42) of patients had different degree of hypertension, while up to 31.0% (13/42) was silent type. There was no statistical difference between the two groups in severity of hypertension, age, gender, duration, abnormal glucose metabolism, and the incidence of hypokalemia( all P>0.05). Adrenaline level was higher in pheochromocytoma group (13.4% vs 9.5%, P=0.004), while noradrenaline level was higher in paraganglioma group (80.8% vs 59.2%, P=0.001). Malignancy (21.4% vs 4.6%, P<0.001) and bigger tumor size [(6.67±3.24)cm vs (5.55±2.76)cm, P=0.024] was more common in paraganglioma group. The maximum tumor volume was 18.0 cm×18.0 cm×10.5 cm vs 14.0 cm×13.0 cm×7.0 cm, while the minimum was 1.8 cm×1.3 cm×1.3 cm vs 1.2 cm×1.0 cm×1.0 cm. There was no significant difference in the pathological manifestations between the two groups. In the study, 11.9% (5/42) of patients in paraganglioma group was misdiagnosed or indefinite at the early diagnosis. Conclusion: Compared with pheochromocytoma, paraganglioma has the characteristics of widely distribution, more various clinical performance, more silent type and higher malignant rate. It is critical to put emphasis on its early diagnosis and treatment.

Coexistence of perfect spin filtering for entangled electron pairs and high magnetic storage efficiency in one setup.

For Entangled electron pairs superconducting spintronics, there exist two drawbacks in existing proposals of generating entangled electron pairs. One is that the two kinds of different spin entangled electron pairs mix with each other. And the other is a low efficiency of entanglement production. Herein, we report the spin entanglement state of the ferromagnetic insulator (FI)/s-wave superconductor/FI structure on a narrow quantum spin Hall insulator strip. It is shown that not only the high production of entangled electron pairs in wider energy range, but also the perfect spin filtering of entangled electron pairs in the context of no highly spin-polarized electrons, can be obtained. Moreover, the currents for the left and right leads in the antiferromagnetic alignment both can be zero, indicating 100% tunnelling magnetoresistance with highly magnetic storage efficiency. Therefore, the spin filtering for entangled electron pairs and magnetic storage with high efficiencies coexist in one setup. The results may be experimentally demonstrated by measuring the tunnelling conductance and the noise power.

Proposal of a new degradation mechanism of enalapril maleate and improvement of enalapril maleate stability in tablet formulation with different stabilizers.

Enalapril maleate (EM) is unstable in poorly designed tablet formulations. To improve the stability of EM, the degradation mechanism should be elucidated. In this study, we found that several commonly used excipients promoted the degradants of EM, particularly a diketopiperazine derivative (DKP). We propose two degradation pathways in which both acid and alkali can promote the formation of DKP, although previous reports suggested that DKP is produced mainly in acidic media. Based on the degradation pathways, we believe that subtle control of the microenvironmental pH can inhibit the formation of DKP. This was confirmed by the observation that the degradation rate became slower when certain organic acids were added to the binary mixtures of EM and excipient. The data showed that the stability of EM in the ternary mixtures was much higher than that in binary mixtures. It was further proved that tablets containing these organic acids produced less DKP after the accelerated test. We also found that the formation of DKP in tablets varied with different ratios of tartaric acid, which was used as a model organic acid. This illustrated that an optimum ratio of tartaric acid is required. These results indicated that the stability of EM in tablet formulation is closely associated with microenvironmental pH and the addition of a suitable organic acid based on the reaction mechanism is an effective strategy for improving the stability of EM.

Genotoxicity of fenpropathrin and fenitrothion on root tip cells of Vicia faba.

The genotoxicity of fenpropathrin and fenitrothion on root tip cells of Vicia faba was studied. The symptoms were investigated about the mitotic index, the micronucleus frequency and chromosomal aberration frequency of root tip cells of Vicia faba which were induced by different concentrations of fenpropathrin and fenitrothion (1 × 10(-10)-1 × 10(-2) g L(-1)). Results showed that fenpropathrin and fenitrothion could induce the micronucleus of root tip cells of Vicia faba. It occurred in a dose-dependent manner. Peaks were observed at 1 × 10( -6) g L(-1) fenpropathrin and 1 × 10(-4) g L(-1) fenitrothion, and micronucleus frequency reached 14.587 ± 1.511‰ and 14.164 ± 1.623‰, respectively. From 1 × 10(-10) g L(-1) to 1 × 10( -6) g L(-1) fenpropathrin and 1 × 10(-4) g L(-1) fenitrothion, the micronucleus frequency increased with the increase of the concentrations, but beyond this range, the micronucleus frequency decreased with the further increase of the concentrations. A similar trend was observed for mitotic index. Moreover, fenpropathrin and fenitrothion could induce various types of chromosome aberration, such as lagging chromosomes, chromosome fragment, chromosome bridge, multipolar, nuclear buds, karyorrhexis, etc.

Alleviation effect of alginate-derived oligosaccharides on Vicia faba root tip cells damaged by cadmium.

Cadmium has been shown to prevent Vicia faba growth by inhibiting cell mitosis. In this study we investigated the role of Alginate-derived Oligosaccharides (ADO) in alleviating Vicia faba root tip cells damaged by 6 and 8 mg L(-1) CdCl2. Micronucleus assay and chromosomal aberration assay were used to determine mitotic index, micronucleus frequency and chromosomal aberration frequency. The results showed that micronucleus frequency of Vicia faba root tip cells was inhibited under all the ADO concentrations. Especially, the inhibition ratio of 0.125% ADO highly reached 66.11 and 67.17% in 6 and 8 mg L(-1) CdCl2, respectively. Furthermore, the mitotic index increased (p < 0.05) and chromosomal aberration frequency decreased (p < 0.05) under all the ADO concentrations. This indicated that ADO had a significant alleviation effect on Vicia faba root tip cells damaged by cadmium.