Liquid-like atoms in dense-packed solid glasses.

Revealing the microscopic structural and dynamic pictures of glasses is a long-standing challenge for scientists1,2. Extensive studies on the structure and relaxation dynamics of glasses have constructed the current classical picture3-5: glasses consist of some 'soft zones' of loosely bound atoms embedded in a tightly bound atomic matrix. Recent experiments have found an additional fast process in the relaxation spectra6-9, but the underlying physics of this process remains unclear. Here, combining extensive dynamic experiments and computer simulations, we reveal that this fast relaxation is associated with string-like diffusion of liquid-like atoms, which are inherited from the high-temperature liquids. Even at room temperature, some atoms in dense-packed metallic glasses can diffuse just as easily as they would in liquid states, with an experimentally determined viscosity as low as 107 Pa·s. This finding extends our current microscopic picture of glass solids and might help establish the dynamics-property relationship of glasses4.

[An investigation on serum antibody level of varicella-zoster virus in healthy population in Beijing].

Objective: To assess the level and trend of varicella-zoster virus (VZV) antibody among healthy population in Beijing in 2017, after the five-year implementation of the two doses varicella vaccination strategy in 2012, and to provide evidence for scientific evaluation of immunization strategy. Methods: A total of 2 144 subjects in ten age groups from 8 districts of Beijing city were recruited in this study using cross-sectional survey based on multi-stage cluster random sampling method. Serum samples were collected and VZV antibody was detected by ELISA. The influencing factors of antibody concentration and positive rate were analyzed and compared with the study in 2012. The antibody concentration and antibody positive rate were analyzed by nonparametric test and χ² test respectively. Results: The ratio of subjects with registered residence in Beijing city to other provinces was 1∶1. The ratio of male to female was 1∶1.08. The median concentration of VZV antibody was 341.4 (78.6, 1 497.8) mIU/ml, and the total antibody positive rate was 71.1% (1 524/2 144). There were significant differences in antibody positive rate (χ²=736.39, P<0.01) and antibody concentration (χ²=740.34, P<0.01) among different age groups. The antibody positive rate generally increased with age (χ²trend=7.32, Ptrend<0.01). Among 862 children under 14 years old, the antibody positive rate of two doses vaccination 72.8% (182/250) was significantly higher than that of one dose vaccination 51.9% (154/297) (χ²=25.14, P<0.01). There was significant difference between 1-4 years old group (χ²=11.71, P<0.01) and 10-14 years old group (χ²=5.95, P=0.02), but not in 5-9 years old group (χ²=3.00, P=0.07). Compared with the study in 2012, the antibody positive rate increased in 5-9 years old group (χ²=14.35, P<0.01) and decreased in 1-4 years old group (χ²=11.51, P=0.01) in 2017. Conclusion: The recommended varicella booster vaccination has significantly improved the VZV antibody level of children in Beijing city. In the future, it is necessary to explore a more optimized two doses varicella vaccination schedule for children in combination with epidemiological evidence.

[Clinical characteristics of patients infected with Chlamydia pneumoniae in Beijing from 2015 to 2019].

Objective: To aralyze the clinical characteristics of Chlamydia pneumoniae infection in Beijing. Methods: Based on Beijing Respiratory Pathogen Surveillance System, acute respiratory infection patients were recruited from 35 different types of sentinel hospitals in Beijing. Their epidemiological and clinical data were systematically collected and clinical specimens were also obtained. Nuclear acid testing was performed for 30 types of respiratory pathogens (including Chlamydia pneumoniae). The identified patients of Chlamydia pneumoniae infection were divided into two groups, the acute upper respiratory tract infection (AURI) group and pneumoniae group. The differences in clinical characteristics, laboratory examination and prognosis were compared by using independent sample t test, Mann-Whitney U test, χ2 test or Fisher's exact probability test. Results: A total of 119 patients of Chlamydia pneumoniae infection were included, including 12 patients in the AURI group and 107 patients in pneumoniae group. Chlamydia pneumoniae infection mainly occurred in people aged from 5 to 44 years, accounting for 81.5% (97/119). The three most common clinical symptoms were cough (92.4%, 110/119), fever (88.8%, 95/107), and sputum production (76.5%, 91/119). White blood cell counts increased in 39.3% (46/117) of patients. Neutrophile granulocyte proportion increased in 39.7% (46/116) of patients. Platelet count increased in 36.9% (41/111) of patients. An increase of the creatine kinase MB isoenzyme (CKMB) was observed in 12 pneumonia patients (24.5%, 12/49). Radiological examination showed that 90.6% (87/105) of patients in the pneumoniae group had pulmonary parenchymal changes; the lesion occurred most commonly in the lower right lung lobe (34.3%, 36/105) and the lower left lung lobe (27.6%, 29/105). Although 73.8% (79/107) of patients in the pneumoniae group were hospitalized, no case received intensive care unit or mechanical ventilation. As to outcomes, one patient developed respiratory failure and 6 patients suffered myocardial injury. No death was observed in this study. The median days of hospitalization and course of illness for pneumonia patients M(P25,P75) were 10.0 (7.0, 13.0) days and 18.0 (13.5, 22.0) days, respectively. Conclusion: Generally, Chlamydia pneumoniae infections in Beijing from 2015 to 2019 were mild, and the main clinical manifestations were cough, fever and sputum. However, most patients in the pneumoniae group caused by Chlamydia pneumoniae still required hospitalization but with a better outcome.

Observation of High-Frequency Transverse Phonons in Metallic Glasses.

Using inelastic neutron scattering and molecular dynamics simulations on a model Zr-Cu-Al metallic glass, we show that transverse phonons persist well into the high-frequency regime, and can be detected at large momentum transfer. Furthermore, the apparent peak width of the transverse phonons was found to follow the static structure factor. The one-to-one correspondence, which was demonstrated for both Zr-Cu-Al metallic glass and a three-dimensional Lennard-Jones model glass, suggests a universal correlation between the phonon dynamics and the underlying disordered structure. This remarkable correlation, not found for longitudinal phonons, underscores the key role that transverse phonons hold for understanding the structure-dynamics relationship in disordered materials.

[Surveillance of immunization effectiveness and titer of type â and type â ¢ polio vaccine in Beijing before and after the adjustment of immunization strategy in 2012-2018].

Objective: To analyze the changing trend of polio vaccine immunization effectiveness and vaccine titer in Beijing in 2012, 2014, 2016 and 2018 before and after the adjustment of polio vaccine immunization program strategy. Methods: According to the convenient sampling method,the vaccination clinics of Chaoyang and Yanqing Districts in 2012, Fengtai and Daxing Districts in 2014, Tongzhou and Pinggu Districts in 2016, Dongcheng and Shunyi Districts in 2018 were selected as monitoring points. A total of 292 children were selected 4-8 weeks after the completion of 3 doses polio vaccine basic immunization which were 3 doses of trivalent oral poliovirus vaccine（tOPV）schedule before the strategy adjustment in 2012-2014 and 1 dose of inactivated poliovirus vaccine (IPV) following 2 doses of bivalent oral poliovirus vaccine (bOPV) sequential schedule after the adjustment in 2016-2018. About 1.0 ml blood samples were collected to detect type Ⅰ and Ⅲ neutralizing poliovirus antibody. A total of 9 oral poliovirus vaccines (8 vaccines in 2012) were selected from different sources of vaccine storage every year to test the vaccine titer using random number method. Results: The [M（P25，P75）] age of 292 children was 5 (5, 6) months, and the ratio of male to female was 1.04 (149/143). In 2012, 2014, 2016 and 2018, 66,72,68 and 86 children were investigated respectively. After basic immunization, antibody positive rates for type Ⅰ and Ⅲ poliovirus were 100%, except 98.61% (71) for type Ⅰ poliovirus in 2014. The neutralizing antibody titer of type Ⅰ and Ⅲ poliovirus was higher in 2016 and 2018 than that in 2012 and 2014 (P<0.001). The average titer of tOPV were (6.05±0.15) and (6.16±0.12) lgCCID50 per dose in 2012 and 2014. The average titer of bOPV were (6.88±0.21) and (6.26±0.14) lgCCID50 per 100 µl in 2016 and 2018 (P<0.001). Conclusion: Before and after the adjustment of polio vaccine immunization strategy in Beijing, the basic immunization success rate of the IPV-bOPV sequential immunization schedule was good as well as full tOPV schedule. The level of polio antibody produced by the IPV-bOPV sequential immunization schedule was higher. After adjustment, bOPV titer in 2016 was significantly higher than those before adjustment, while bOPV titer decreased significantly in 2018.

[MiR-222-3р Regulates the Proliferation and Differentiation of C2C12 Myoblasts by Targeting BTG2].

MiR-222-3р has been implicated in tumor cell proliferation and has an important role in the differentiation and maturation of myogenic cells. However, its role in skeletal myoblast proliferation is still unclear. In this study, we found that miR-222-3р expression increases initially and then decreases during C2C12 myoblast proliferation. Using synthetic miRNA mimics and inhibitors in gain- or loss-of-function experiments, we snowed that miR-222-3р overexpression in C2C12 cells promotes myoblast proliferation and represses myofiber formation, while miR-222-3р downregulation has the opposite effect. Using a prediction program, BTG2 was identified as a possible target gene of miR-222-3р. During myogenesis, miR-222-3р mimics repress BTG2 expression, while miR-222-3р inhibitors promote BTG2 expression. Using dual-luciferase reporter assay, we further demonstrated that miR-222-3р specifically targets BTG2. Additionally, we show that siRNA-mediated downregulation of BTG2 expression in C2C12 myoblasts promotes the proliferation and suppresses differentiation. In conclusion, we provide a novel insight into the mechanism by which miR-222-3р regulates the proliferation and differentiation of C2C12 myoblasts by targeting BTG2. This information contributes to our understanding of the role of miRNAs in skeletal muscle development.

[Accuracy analysis of computer assisted navigation for condylectomy via intraoral approach].

OBJECTIVE: To explore the application accuracy of virtual preoperative plan after the condylectomy via intraoral approach under computer assisted surgical navigation, and to analyze the location and cause of the surgical deviation to provide reference for the surgical procedure improvement in the future. METHODS: In the study, 23 cases with condylar hypertrophy (11 with condylar osteochondroma and 12 with condylar benign hypertrophy) in Department of Oral and Maxilloficial Surgery, Peking University School and Hospital of Atomatology from December 2012 to December 2016 were treated by condylectomy via intraoral approach under computer assisted surgical navigation. The patient's spiral CT data were imported into ProPlan software before operation, and the affected mandibular ramus was reconstructed three-dimensionally. The condylar osteotomy line was designed according to the lesion range, and the preoperative design model was generated and introduced into the BrainLab navigation system. Under the guidance of computer navigation, the intraoral approach was used to complete the condylar resection according to the preoperative design of the osteotomy line. Cranial spiral CT of the craniofacial region was taken within one week after operation. three-dimensional reconstruction of the mandibular ramus at the condylectomy side was performed, and the condylar section was divided into six segments (anterolateral, anterior, anteromedial, posteromedial, posterior, and posterolateral) and the corresponding regional measurement points P1 to P6 were defined. Then the preoperative virtual model and the postoperative actual model were matched by Geomagic studio 12.0 to compare the differences and to analyze the accuracy of the operation. RESULTS: All the patients had successfully accomplished the operation and obtained satisfactory results. Postoperative CT showed that the condyle lesion was completely resected, and the condylar osteotomy line was basically consistent with the surgical design. No tumor recurrence or temporomandibular joint ankylosis during the follow-up period. The postoperative accuracy analysis of the condylar resection showed that the confidence intervals measured by the six groups of P1 to P6 were (-2.26 mm, -1.89 mm), (-2.30 mm, -1.45 mm), (-3.37 mm, -2.91 mm), (-2.83 mm, -1.75 mm), (-1.13 mm, 0.99 mm), and(-1.17 mm, 0.17 mm), where P3 group was different from the other 5 groups. There was no significant difference between the P5 and P6 groups and the difference between the other four groups was statistically significant. CONCLUSION: Under the guidance of computer navigation, the intraoral approach can be performed more accurately. The surgical deviation of each part of the osteotomy surface is mainly due to excessive resection. The anterior medial area of the anterior medial condyle represents the most excessive resection. The posterior and posterior lateral measurement points represent the posterior condylar area. The average deviation is not large, but the fluctuation of the deviation value is larger than that of the other four groups. The accuracy of computer-assisted subtotal resection has yet to be improved.

[Survey of the acceptance status of HPV self-sampling screening in female population for cervical cancer].

Objective: To investigate the acceptance of HPV self-sampling mode in cervical cancer screening population and explore its feasibility. Methods: From March 5 to 15, 2018, researchers investigated women who participated in cervical cancer screening organized by Beijing Shunyi Women's and Children's Hospital in the form of questionnaires. Questionnaires were conducted on their acceptance status and the factors that affect the self-sampling experience. The specific contents of the questionnaires were as follows: (1) the experience of using self-sampling included operability, comfortable, sample time-consuming, bleeding or not after sampling; (2) psychological changes after self-sampling, including the willingness to accept self-sampling again, the worrying problems during self-sampling process. According to whether or not have operating video guidance, the self-sampling experience and psychological changes after self-sampling were compared. Results: (1) There were 1 375 women participated in the questionnaire survey, and 86.55% (1 190/1 375) of them thought the self-sampling was convenient, 78.40% (1 078/1 375) thought it was not uncomfortable, 88.58% (1 218/1 375) thought the sampling time was fast (less than 5 minutes), 94.04% (1 293/1 375) self-sampling without bleeding; and 83.27% (1 145/1 375) were willing to self-sampling for cervical cancer screening again, 85.82% (1 180/1 375) were afraid of inaccurate sampling. (2) Among the 1 375 women, 1 202 were in the video guidance group and 173 were in the non-guidance group. The self-sampling experience of women in video guidance group was better than those of non-guidance group in operability, comfortable, sampling time-consuming and bleeding after sampling. The proportion of women who willing to self-sampling again was higher than that of non-guidance group (86.69% vs 59.54%, respectively). The proportion of women who worried operating incorrectly was lower than that of non-guidance group (11.23% vs 32.37%, respectively). The differences were significant (all P<0.05). Conclusions: Self-sampling for HPV testing in cervical cancer screening is easy to operate and has little discomfort complaint. It is feasible in cervical cancer screening. Operational video guidance during the screening process could effectively improve the women's experience and willingness to self-sampling again in the future.

Size effect on dynamics and glass transition in metallic liquids and glasses.

The relaxation dynamics and glass transition in finite-sized metallic liquid droplets were investigated via molecular dynamic simulations in model monoatomic Ta and binary Cu50Zr50 metallic liquids. We find that the droplet size has a significant impact on liquid dynamics and glass transition. Glass transition temperature and structural relaxation time exhibit strong size dependence and decrease drastically as the droplet is smaller than a certain size. It is revealed that this results from a liquid-like surface layer (∼1 nm thick) of droplets, in which the dynamics is much faster than the interior of droplets. A proposed scaling relationship can well describe the size dependent behavior of the glass transition temperature in metallic liquid droplets. These findings provide insight into the dynamics of metallic liquid droplets and plausible understanding of recent novel experimental observations. Apart from temperature and pressure, size may be another important parameter for potentially tuning the properties of metallic liquids and glasses in nanometer scale.

[Feasibility and effectiveness of percutaneous ventricular septal defect closure under solely guidance of echocardiography].

Objective: To compare the efficacy and safety of percutaneous ventricular septal defect (VSD) closure under solely guidance of echocardiography and fluoroscopy. Methods: The retrospective study was conducted at Fuwai Hospital, between February 2014 and February 2015. The patients were divided into two groups. VSD closure was conducted in 42 patients under solely guidance of echocardiography, and 100 patients who were treated with percutaneous catheter closure under fluoroscopy guidance were selected as a control group. The baseline characteristics, procedural time and complications were recorded and assessed. Results: There were no significant differences in terms of age, gender and pre-operative echocardiographic characteristics (all P>0.05). Percutaneous VSD closure under traditional fluoroscopy guidance was successful in 95 patients (95%). The procedural time was (54.7±12.5) minutes. The symmetrical occluders diameter was (6.9±1.8) mm. Four patients had postoperative residual shunt, one patient developed left bundle branch block, and 6 patients developed new tricuspid regurgitation. Percutaneous VSD closure under only transthoracic echocardiography (TTE) guidance was successful in 39 patients (93%). Because of delivery catheter passage failure through the defect, one case required conversion to perventricular closure via a small transthoracic incision under transesophageal echocardiography (TEE) guidance. The other two cases underwent surgical repair because of residual shunt with more than 2 mm after closure. The procedural time was (40.3±13.2) minutes. The symmetrical occluders diameter was (6.5±1.2) mm. Four patients had postoperative residual shunt that disappeared after 1 month follow-up, and one patient developed right bundle branch block which disappeared 3 days later. During (9.3±3.6) months follow-up, there were no other complications, such as pericardial effusion, occluder malposition, atrioventricular block, aortic valve regurgitation, and aggravating tricuspid regurgitation in each group. However, the total operation time, diameter of VSD occluder, total mild complications, and the equipment cost in the study group were less than that in the control group (P<0.05). Conclusion: Percutaneous VSD closure can be successfully performed under sole guidance of echocardiography with outcomes similar to those achieved with fluoroscopy guidance.

[Study on clinical management of HPV(+)/Pap(-) during cervical cancer screening].

Objective: To study the clinical management way for HPV(+)/papanicolaou (Pap)(-) during cervical cancer screening. Methods: To analyze retrospectively the data from the patients who had loop electrical excision procedure (LEEP) for biopsy confirmed cervical intraepithelial neoplasia (CIN) Ⅱ in Peking University People's Hospital from Jan. 2010 to Dec. 2014. Results: (1) For biopsy confirmed CIN Ⅱ, HPV positive rate was 98.5% (135/137), Pap test positive [≥atypical squamous cell of undetermined significance (ASCUS)] rate was 69.3% (95/137), there was significant difference between them (χ(2)=43.32, P<0.01). (2) For the 42 patients with HPV(+)/Pap(-), whose cytology slides were reviewed again. Among them, the interpretations of there were 16 cases confirmed as the same before, while 26 cases were changed to abnormal (≥ASCUS). Cytology be misdiagnosed was 19.0% (26/137) at the first review. Among the 26 cases, 13 (50.0%) cases were missed for the little amount of abnormal cells, 8 (30.8%) cases for mild atypical morphology changed; the other 5 (19.2%) cases missed for stain problems. (3) For the cervical LEEP samples, 37 cases of the pathology diagnosis were upgrade to CIN Ⅲ(+), among them, 2 cases of microinvasive cervical carcinoma, 1 case of invasive cancer, 34 cases of CIN Ⅲ; 37 cases were CINⅠ or no lesion found; 63 cases were still CIN Ⅱ. Four to six months later after LEEP, the cytology abnormal rate was 11.7% (16/137), and the HR-HPV positive rate was 34.3% (47/137). Conclusions: Compared with cytology alone, cytology combined with HPV testing increase the sensitivity of cervical high grade lesion. For the cases of HPV(+)/Pap(-) cases, the cytology slides should be reviewed. The quality control of cervical exfoliate sample collection and interpretation should be strengthened. LEEP procedure is not only a treatment method, but also it could provide samples to confirm the diagnosis.

Effects of atomic interaction stiffness on low-temperature relaxation of amorphous solids.

While low-temperature relaxations show significant differences among metallic glasses with different compositions, the underlying mechanism remains mysterious. Using molecular dynamics simulation, low-temperature relaxation of amorphous solids is investigated in model systems with different atomic interaction stiffness. It was found that as the interaction stiffness increases, the low-temperature relaxation is enhanced. The fraction of mobile atoms increases with increasing interaction stiffness, while the length scale of dynamical heterogeneity does not change. The enhanced relaxation may be due to increased dynamical heterogeneity. These findings provide a physical picture for better understanding the origin of low-temperature relaxation dynamics in amorphous solids, and the experimentally observed different ß-relaxation behaviors in various metallic glasses.

Effect of local structures on crystallization in deeply undercooled metallic glass-forming liquids.

The crystallization mechanism in deeply undercooled ZrCu metallic glass-forming liquids was investigated via molecular dynamics simulations. It was found that the crystallization process is mainly controlled by the growth of crystal nuclei formed by the BCC-like atomic clusters, consistent with experimental speculations. The crystallization rate is found to relate to the number of growing crystal nuclei in the crystallization process. The crystallization rate in systems with more crystal nuclei is significantly hindered by the larger surface fractions of crystal nuclei and their different crystalline orientations. It is further revealed that in the crystallization in deeply undercooled regions, the BCC-like crystal nuclei are formed from the inside of the precursors formed by the FCC-like atomic clusters, and growing at the expense of the precursors. Meanwhile, the precursors are expanding at the expense of the outside atomic clusters. This process is consistent with the so-called Ostwald step rule. The atomic structures of metallic glasses are found to have significant impact on the subsequent crystallization process. In the Zr85Cu15 system, the stronger spatial correlation of Cu atoms could hinder the crystallization processes in deeply undercooled regions.

Developmental methylation pattern regulates porcine GPR120 expression.

DNA methylation is an important component of the epigenetic machinery and plays a critical role in transcriptional regulation. It mostly occurs in CpG abundant regions, known as CpG islands (CGIs). G protein-coupled receptor 120 (GPR120) functions as an omega-3 fatty acid receptor and is involved in multiple-biological processes, including lipogenesis. Herein, we show that GPR120 is highly expressed in porcine mature adipose tissue and is positively associated with adipose tissue development (r = 0.86, P < 0.01). We also predicted 5 CGIs across the GPR120 genomic sequence and investigated their methylation status using the MassArray approach. Our results show that these CGIs exhibit significantly different methylation states (P(CGI) < 0.01), and that the DNA methylation of GPR120 5ꞌ-untranslated and first exon regions can negatively regulate its expression levels. This study will aid further investigations on the epigenetic mechanism regulating GPR120 expression.

[Clinical possibility of low ligation of inferior mesenteric artery and lymph nodes dissection in laparoscopic low anterior resection].

OBJECTIVE: To investigate the clinical possibility of low ligation of inferior mesenteric artery (IMA) and lymph nodes dissection in laparoscopic low anterior resection. METHODS: Data was collected retrospectively from 216 patients who underwent laparoscopic low anterior resection in our hospital from June 2011 to January 2015.Patients were divided into control group (132 cases) and observation group (84 cases). The observation group was treated with low ligation of IMA and lymph nodes dissection, and the control group was cured by high ligation of IMA and lymph nodes dissection. We analyzed the operation time, the number of lymph nodes dissection, the number of lymph nodes removed around the root of IMA, the rate of lymph node metastasis around the root of IMA, the incidence of anastomotic leakage and the ventilation time after the operation. RESULTS: There was no significant difference between the two group in the pre-operative data, operation time, the number of lymph nodes dissection the number of lymph nodes removed around the root of IMA, the rate of lymph node metastasis around the root of IMA and the incidence of anastomotic leakage (P>0.05). The observation group were significantly better than the control group the in the ventilation time after the operation (P<0.05). The follow up time was 12 to 67 months. The median follow up time was 37 months. One patient in observation group died of cardiovascular disease. One patient in control group died of metastatic carcinoma. CONCLUSION: Detection of low ligation of inferior mesenteric artery and lymph nodes dissection in laparoscopic low anterior resection is safe and practicable, which should be widely applied.

Effectiveness of microsatellite and single nucleotide polymorphism markers for parentage analysis in European domestic pigs.

Parentage analysis and individual identification are recent, promising methods that have been applied to evolutionary and ecological studies, as well as conservation management. Parental exclusion relying on polymorphic microsatellites has been used worldwide in parentage determination, while the low mutation rate and genotyping error rate of single nucleotide polymorphisms (SNPs) make them another important marker for pedigree tracing. Here, we compared the effectiveness of microsatellites and SNP markers in European pigs. We also measured and presented the minimum and optimal criteria for SNP markers to be used in paternity and identity analysis. Our findings may contribute to the development of techniques for future molecular evolution and conservation studies, as well as breeding programs.

Promoter and first exon methylation regulate porcine FASN gene expression.

DNA methylation is a stable epigenetic mark mediating gene expression. Methylation is crucial for diverse biological processes, including aging and embryo development. FASN (fatty acid synthase) plays an important role in de novo lipogenesis, through catalyzing the reductive synthesis of long-chain fatty acids. In this study, we investigated the FASN gene expression pattern and corresponding DNA methylation status in the inner layer of backfat from Jinhua pigs at different developmental stages. Our results showed that FASN gene expression increases with age and is positively associated with adipocyte volume (r = 0.98, P < 0.01). In addition, the DNA methylation level for the first exon (0.11, CGI 3) of the FASN gene is approximately 8-fold lower than levels for its promoter (0.94, CGI 1&2) (two-way ANOVA, PCGI < 0.01). The association analysis revealed that both promoter (r = -0.944, P < 0.01) and first exon methylation (r = -0.774, P < 0.01) are significantly and negatively correlated with FASN gene expression. Our results will benefit future investigations of the epigenetic mechanism underlying FASN gene expression.

Quantitative changes in mitochondrial DNA copy number in various tissues of pigs during growth.

Mitochondrial DNA (mtDNA) content is dependent on the energy requirements of tissues. To date, no comprehensive study has been conducted to examine mtDNA copy number variations in pigs. In the current study, quantitative polymerase chain reaction was performed to quantify the mtDNA copy number in 15 pig tissue types at 5 growth stages from embryo to adult. Observable differences in mtDNA content were detected in the tissues, including a 6-fold greater mtDNA content in the heart compared with the lung of 180-day-old samples. mtDNA content in the heart, longissimus dorsi muscle, psoas major muscle, kidney, brain, ovary, and subcutaneous adipose increased with growth. Expression of the replicative mitochondrial helicase (TWINKLE), which regulates mtDNA turnover, was significantly associated with changes in mtDNA copy numbers across tissues during growth (r = 0.33, P = 0.01). We demonstrated that the expression levels of mitochondrial genes were positively correlated with mtDNA copy number.