Objective To explore the role and molecular mechanism of major vault protein (MVP) in tumor-associated macrophages in the occurrence and development of liver cancer. Methods The expression of MVP in macrophages was analyzed by bioinformatics method and multi-fluorescent immunohistochemical staining. Mice with MVP deficiency in macrophages were constructed by Cre/LoxP recombinant enzyme system. The proliferation and migration abilities of tumor cells were detected by cloning formation and Transwell migration assays. The effect of MVP in macrophages on tumorigenesis and development was investigated by mouse primary liver cancer model and subcutaneous tumor transplantation model. The effect of MVP on the tumor microenvironment was investigated by multi-fluorescent immunohistochemical staining. The effect of MVP on CD8⁺ T cells was detected by cell co-culture, flow cytometry, qPCR, and ELISA. Results The high expression of MVP in tumor-associated macrophages. The downregulation of the expression of MVP in tumor-associated macrophages compared with para-carcinoma tissues. MVP deficiency in macrophages promoted the proliferation and migration of tumor cells (P<0.05), promoted the development of tumor in vivo (P<0.05), formed an immunosuppressive microenvironment and weakened CD8⁺ T cell-mediated anti-tumor immunity (P<0.05). Conclusion MVP deficiency in macrophages can promote the occurrence and development of liver cancer by suppressing the function of CD8⁺ T cells.

Objective To explore the role and molecular mechanism of Lnc-BM in the occurrence and development of gastric cancer (GC). Methods GC tissues and paired adjacent normal tissues of 36 GC patients were collected, and the expression of Lnc-BM was detected by RT-qPCR. Colony formation and CCK-8 assays were used to investigate the proliferation of GC cells. The migration and invasion properties of GC cells were investigated via Transwell assay. RNA pull-down assay was applied to confirm the interaction between FASTK and Lnc-BM. Western blot assay was used to detect FASTK protein level in Lnc-BM overexpressing or knockdown cells. Mitochondrial respiratory capacity and the related proteins expression levels were detected by Seahorse and Western blot assays, respectively. Lnc-BM stably overexpressing GC cells were constructed and then injected subcutaneously into nude mice. The tumor growth was observed. Results Lnc-BM was highly expressed in GC tissues compared with their paired adjacent normal tissues. Lnc-BM overexpression significantly promoted GC cells proliferation migration and invasion, while Lnc-BM knockdown inhibited GC cells proliferation, migration and invasion (P < 0.05). RNA pull-down experiment demonstrated that Lnc-BM can directly bind to FASTK. Western blot results indicated that overexpression of Lnc-BM increased the protein levels of FASTK, while knockdown of Lnc-BM inhibited the expression of FASTK (P < 0.05). Compared to the control group, overexpression of Lnc-BM increased the levels of mitochondria associated proteins, such as MT-ND6 and TOM20 (P < 0.05). Seahorse results indicated that overexpression of Lnc-BM enhanced mitochondrial respiratory capacity (P < 0.05). Knocking down FASTK in Lnc-BM stably overexpressing cells can reverse the increase in mitochondrial respiratory capacity caused by Lnc-BM overexpression (P < 0.05). In vivo, the results of subcutaneously implanted tumor model in nude mouse showed that Lnc-BM overexpression promoted the tumor growth (P < 0.05). Conclusion Lnc-BM promotes GC progression by regulating mitochondrial respiratory function through the FASTK/MT-ND6 axis.

Objective To observe the value of augmented reality(AR)navigation system for assisting CT-guided puncture of pulmonary nodules in dog models.Methods Five healthy dogs were selected,and 4 target lung rings were implanted in each dog to build pulmonary nodule models.Deferring to crossover design,CT-guided punctures were performed with or without AR navigation 2 and 4 weeks after successful modeling,respectively,while punctures with AR navigation were regarded as AR group and the others as conventional group,respectively.The time duration of puncturing,the times of CT scanning,of needle adjustment,and the deviation distance between needle pinpoint to the center of pulmonary nodule shown on three-dimensional reconstruction were compared between groups.Results The duration time of puncture in AR group and conventional group was(13.62±5.11)min and(20.16±4.76)min,respectively.In AR group,the times of CT scanning,of needle adjustment,and the deviation distance was 2.40±0.50,2.75±0.44 and(2.94±1.92)mm,respectively,while in conventional group was 3.10±0.64,3.70±0.57 and(4.90±3.38)mm,respectively.The introduction of AR navigation was helpful to shortening the duration of puncture,reducing times of CT scanning and needle adjustment,also decreasing positioning error of needle pinpoint(all P＜0.05).In contrast,the variance of puncture sequences and dogs had no obvious effect on the results(both P＞0.05).Conclusion AR navigation system could improve accuracy and efficiency in CT-guided puncture of pulmonary nodules in dog models.

Objective To explore the main factors affecting the MV imager projection offset in the machine performance check(MPC)for Varian Vital Beam linear accelerator.Methods The MV imager projection offsets in the MPC after repairing the MV imaging arm encoder of shoulder motor,locking the treatment couch,and isocenter calibration were analyzed.Results MPC results revealed that the MV imager projection offset after repairing the MV imaging arm encoder of shoulder motor was(0.310±0.001)mm,significantly less than(0.450±0.010)mm in the blank group.The difference in MV imager projection offset between the isocenter calibration group and the blank group was trivial.The MV imager projection offset after locking the treatment couch was(0.240±0.030)mm,significantly less than(0.450±0.010)mm in the blank group.When MPC was carried out after repairing the imaging arm encoder and performing isocenter calibration,there was no significant statistical difference in MV imager center offset between the locked and unlocked treatment couch.Conclusion The damage of MV imaging arm encoder of shoulder motor is the main factor causing abnormal MV imager projection offsets.Locking the treatment couch before the MV imaging center check can reduce the results,but it cannot eliminate the MV imager projection offset.

The occurrence of gastric cancer is closely related to environmental, genetic, and epigenetic factors. Currently, RNA modification is a research frontier and hotspot in the field of epigenetics. With the advancements in analytical chemistry and high-throughput sequencing technologies, new technologies and methods of exploring RNA modification are constantly being presented. Numerous studies have confirmed the involvement of RNA modifications in the occurrence and development of various diseases. Recent studies have shown that RNA modifications such as m6A, m5C, and ac4C regulate the malignant progression of various tumors, including gastric cancer, liver cancer, colorectal cancer, and leukemia. This article systematically reviews the research status and mechanism of different RNA modifications in the occurrence and development of gastric cancer, as well as discusses its potential value in the diagnosis and treatment of gastric cancer.

Background Air pollutants PM_2.5 and its adsorbed metal elements are important factors affecting public health. Objective To explore the distribution characteristics and sources of metal elements in atmospheric PM_2.5 in Lanzhou from 2019 to 2020, and to assess the health risks of metal elements to different groups of residents through inhalation. Methods From January 2019 to December 2020 in two districts of Lanzhou City (Chengguan District and Xigu District), regular PM_2.5 and metal elements [antimony (Sb), aluminum (Al), arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), mercury (Hg), lead (Pb), manganese (Mn), nickel (Ni), selenium (Se), and thallium (Tl)] were regularly monitored, and their concentrations were described by the median (M) and 25^th and 75^th percentiles (P₂₅, P₇₅) as not following a normal distribution (because the detection rates of the five elements Be, Cr, Hg, Ni, and Se were less than 70%, the five elements were not included in subsequent analysis), and then compared with the secondary concentration limits in the Ambient Air Quality Standards (GB 3095-2012). The differences between the medians of the two groups were compared by the Mann-Whitney U rank sum test, and the differences among the medians of multiple groups were compared by the Kruskal-Wallis H rank sum test; the enrichment factor (EF) method and principal component analysis were used to evaluate the pollution degree of the metals and their sources; the health risks of five non-carcinogenic metals (Sb, Al, Pb, Mn, and Tl) and two carcinogenic metals (As and Cd) in PM_2.5 were evaluated by hazard index (HI) and hazard quotient (HQ) using the incremental lifetime cancer risk (LCR) model and the non-carcinogenic risk assessment model, respectively. Results The PM_2.5 concentrations [M (P₂₅, P₇₅)] in Lanzhou City were 38.50 (26.00, 65.00) and 41.00 (29.00, 63.10) μg·m⁻³ in 2019 and 2020, respectively, and the difference was not statistically significant (Z=−0.989, P > 0.05). The average levels of the metal elements from high to low were: Al > Pb > Mn > As > Cd > Sb > Tl, and the annual average concentration of each metal element in 2019 was higher than that in 2020 (P<0.05). The M ( P₂₅, P₇₅) of PM_2.5 concentrations in Chengguan and Xigu districts were 52.98 (17.00, 61.00) and 55.40 (17.00, 67.00) μg·m⁻³, respectively, with no statistically significant differences (P<0.05); the concentrations of Sb and Al in Chengguan District were lower than those in Xigu District (P<0.05), and the concentrations of other metal elements were not different between the two areas (P>0.05). There were seasonal differences in the concentrations of PM_2.5 and seven metal elements in Lanzhou City (except P_Al=0.007, the other P_s < 0.001). The results of the enrichment factor method showed that the EF values of the six metals (Sb, Al, As, Cd, Pb and Tl) were all greater than 1. Among them, except As, the EF values of other metal elements were all greater than 10, and the EF values of Al and Cd were both greater than 100. The results of principal component analysis showed that the variance contributions of the three principal components were 45.61%, 24.22%, and 14.42%, and the cumulative contribution reached 84.25%. The principal component 1 included Pb, As, Cd, and Sb, the principal component 2 included Al and Mn, and the principal component 3 contained Tl. The non-carcinogenic risks of the five metals were, in descending order, Al > Mn > Pb > Tl > Sb, among which the HQ values of the remaining four metals were less than 1 for adults and children, except the HQ value of Al for adults, which was greater than 1. The ILC values of carcinogenic metal As for adult males, adult females, and children were 2.68×10⁻⁵, 2.51×10⁻⁵, and 1.45×10⁻⁵, respectively; the ILC values of carcinogenic metal Cd for adult males, adult females, and children were 1.53×10⁻⁶, 1.43×10⁻⁶, and 8.26×10⁻⁷, respectively. Conclusion There is pollution of atmospheric PM_2.5 and its adsorbed metal elements in Lanzhou. As and Cd elements may pose potential carcinogenic risks to the residents.

Background Polycyclic aromatic hydrocarbons (PAHs) are one of the most widely distributed and harmful organic pollutants in the atmosphere. Objective To investigate the distribution characteristics and composition sources of PAHs in the atmosphere of two districts of Lanzhou from 2019 to 2020 and evaluate the health risks of PAHs via inhalation to different populations. Methods The PAHs concentrations in two urban areas (Chengguan District and Xigu District) of Lanzhou City from January 2019 to December 2020 were regularly monitored. Mann-Whitney U test was used to compare differences in target pollutant concentrations between the two areas. Diagnostic ratio method and principal component analysis were adopted for source identification. Incremental lifetime cancer risk (ILCR) model was applied to evaluate the health risks of PAHs. Results The M (P₂₅, P₇₅) PAHs concentrations in Chengguan District and Xigu District were 24.04 (14.59, 41.81) ng·m⁻³ and 25.97 (18.59, 42.56) ng·m⁻³, respectively, with no significant difference (Z=−0.970, P>0.05). As to seasonal distribution, most PAHs monomer concentrations in Chengguan District were higher than those in Xigu District in summer, and the concentrations of benzo[a]anthracene and benzo[g,h,i]perylene in Chengguan District were also higher than those in Xigu District in spring and autumn (P<0.05), but there were no significant differences in PAHs monomer concentrations between the two urban areas in winter (P>0.05). Ring number of PAHs exhibited seasonal fluctuations. In winter and spring, the highest proportions in Chengguan District and Xigu District were both 4-ring PAHs (37.32%-41.73%, 35.20%-39.66%), and in summer and autumn, the highest proportions were both 2- and 3-ring PAHs (39.38%-49.54%, 47.17%-51.23%). The results of diagnostic ratio method revealed mixed atmospheric PAHs sources in the two urban areas, including fossil fuel, coal, and biomass combustion. The results of principal component analysis showed that the cumulative contribution rate of the four principal component factors reached 79.54%. Principal component 1 included phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene; principal component 2 included acenaphthene and dibenzo[a,h]anthracene; principal component 3 was fluorene; principal component 4 was naphthalene. The results of health risk assessment showed that the ILCR values of adult males, adult females, and children in Chengguan District were 2.30×10⁻⁶, 2.16×10⁻⁶, and 1.73×10⁻⁶, respectively; and those in Xigu District were 1.58×10⁻⁶, 1.48×10⁻⁶, and 1.19×10⁻⁶, respectively; all were greater than 10⁻⁶. Conclusion PAHs pollution exists in the atmosphere of the two urban areas of Lanzhou City, mainly comes from mixed sources of fossil fuels, coal, and biomass burning, and may pose potential carcinogenic risks to the population.

Objective:To analyze the 6-year operation faults of PHILIPS Brilliance big bore CT, identify the common problems, make corresponding maintenance plans, reduce the incidence of failures, and carry out simulation prediction of the occurrence rate of failures in the next few years.Methods:The failure data of Brilliance big bore CT from June 2012 to June 2018 were collected, and the curve estimation function in SPASS 19.0 software and the pareto diagram were used to analyze the relationship between the number of failures, time and failure types, and the prediction was made.Results:A total of 28 faults occurred during the 6-year opeation of Brilliance big bore CT. During the first half year, five times of faults occurred with the highest fault rate and then tended to stabilize. The linear function model was obtained using the curve estimation: y=-0.033 x+ 2.099( y for the number of fault, unit for times, x for the unit of time for half a year), the model of R2=0.003. In the next three years, approximately twice faults occurred within half year. The pareto chart showed that 16 faults occurred during data collection, including 3 faults in the treatment bed and 3 faults in the power supply system, respectively. The accumulative ratio of the above three faults was 71.4%, which were the main fault sources. Conclusion:The fault statistical analysis of Brilliance big bore CT is helpful for department maintenance personnel to better understand CT, develop effective maintenance programs, reduce the occurrence of faults, and predict the incidence of faults in the future.

Objective: To explore the effects of temperature on the daily cases of varicella. Methods: The data of daily cases of varicella was collected during 2008 to 2016 in Lanzhou from National Notifiable Disease Report System, and the meteorological data at the same period was integrated from Gansu Meteorological Administration. Distributed lag nonlinear model was fitted to reveal the relationship between the daily mean temperature and the daily cases of varicella and susceptible population. The minimum morbidity temperature was defined as the reference for the estimation of RRs in different temperature level (-5.2 ℃, 1.7 ℃, 20.1 ℃ and 25.4 ℃). Results: The total of 21 254 cases were reported from 2008 to 2016, of which the ratio of male to female was 1.28 (11 951/9 303) and people aged 6-14 years accounted for 52.87%. The relationship between the daily mean temperature and the daily cases of varicella was M type. For all subjects, the accumulative effects of temperature had statistical significance from lag 0-14 d when temperatures was at -5.2 ℃, 1.7 ℃ and 20.1 ℃,while the RRs (95%CI) were 1.87 (1.64-2.12) , 1.33 (1.10-1.62) ,1.60 (1.38-1.86) ,while from lag 0-7 d when temperatures was at 25.4 ℃,and the RR (95%CI) was 2.51 (1.93-3.27) . The RR value of accumulative effects was 6.23(95%CI: 4.38-8.86) on lag 7 d when temperatures was at -5.2 ℃, which was the highest value at different temperature during lag days. The cumulative effects trends of different temperatures were similar for different gender population or different age subjects. However, the cumulative effects of was highest for children aged 6-14 years among all subjects, and the value of RR was 6.12 (95%CI:3.71-10.10) on lag 5d when temperatures was at -5.2 ℃. Conclusion We conclude that the increasing risk of varicella is associative with low and high temperature in Lanzhou. The effects of low temperature are stronger than those of high temperature. The children aged 6-14 years belong to the high-risk population of varicella.

OBJECTIVETo study the influences of carbon disulfide (CS2) exposure on fatty acid metabolism in apolipoprotein E (ApoE) knockout mice and C57BL/6J mice.

METHODSTwenty-four male ApoE knockout mice were randomly and equally divided into four groups: a CS2-exposed normal diet group, a CS2-unexposed normal diet group, a CS2-exposed high-fat diet group, and a CS2-unexposed high-fat diet group. Twenty-four C57BL/6J male mice were divided into four groups in the same way. The CS2-exposed groups were exposed to CS2 (1 g/m(3)) by static inhalation for 5 hours a day, 5 days a week. After two weeks, the whole blood of mice was collected. Methyl ester derivatization of fatty acids was performed using an acid-catalyzed method. Fatty acid contents before and after exposure were compared by gas chromatography-mass spectroscopy.

RESULTSThere were significant differences in fatty acid contents of mice between the four groups. For the C57BL/6J mice, the arachidic acid contents in the CS2-exposed high-fat diet group were significantly lower than those in the CS2-unexposed high-fat diet group (P = 0.045 0). For the ApoE knockout mice, the arachidonic acid contents in the CS2-exposed normal diet group were significantly lower than those in the CS2-unexposed control diet group (P = 0.045 2). For the ApoE knockout mice, the γ-linolenic acid contents in the CS2-exposed high-fat diet group were significantly higher than those in the unexposed high-fat diet group (P = 0.044 7).

CONCLUSIONExposure to CS2 can induce fatty acid metabolism disorder in mice, indicating that CS2 may increase the risk of atherosclerosis and other cardiovascular diseases.

Administration, Inhalation ; Animals ; Apolipoproteins E ; genetics ; Atherosclerosis ; Carbon Disulfide ; toxicity ; Diet, High-Fat ; Fatty Acids ; chemistry ; Lipid Metabolism ; drug effects ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout