[Surgical complications of totally implantable venous access port in children with malignant tumors].

OBJECTIVE: To summarize the surgical experience of totally implantable venous access port in children with malignant tumors, and to explore the coping methods of surgical complications. METHODS: The clinical data of 165 children with malignant tumors implanted in totally implantable venous access port in Department of Pediatric Surgery, Peking University First Hospital from January 2017 to December 2019 were retrospectively analyzed. The operation process, complications and treatment of complications were observed and counted. RESULTS: The children in this group were divided into external ju-gular vein incision group (n=27) and internal jugular vein puncture group (n=138) according to different surgical methods, and the latter was divided into ultrasound guided puncture group (n=95) and blind puncture group (n=43). No puncture complications occurred in the external jugular vein incision group, and the average time for successful catheterization and the number of times for catheter to enter the superior vena cava were more than those in the internal jugular vein puncture group [(9.26±1.85) min vs. (5.76±1.56) min, (1.93±0.87) times vs. 1 time], with statistical significance. The average time of successful catheterization, the success rate of one puncture, the average number of punctures and the incidence of puncture complications in the ultrasound guided right internal jugular vein puncture group were better than those in the blind puncture group [(5.36±1.12) min vs. (6.67±1.99) min, 93.68% (89/95) vs. 74.42% (32/43), (1.06±0.24) times vs. (1.29±0.55) times, 2.11% (2/95) vs. 11.63% (5/43)], with statistically significant differences. The total incidence of complications in this study was 12.12% (20/165). Pneumothorax occurred in 1 case, artery puncture by mistake in 1 case, local hematoma in 5 cases, venous access port related infection in 4 cases (venous access port local infection in 2 cases, catheter related blood flow infection in 2 cases), subcutaneous tissue thinning on the surface of port seat in 2 cases, port seat overturning in 1 case, poor transfusion in 4 cases (catheter discount in 1 case, catheter blockage in 3 cases), and foreign bodies gathered around the subcutaneous pipeline in 2 cases. There were no complications, such as catheter rupture, detachment and catheter clamping syndrome. CONCLUSION: Totally implantable venous access port can provide safe and effective infusion channels for children with malignant tumors. Right external jugular vein incision and ultrasound-guided right internal jugular vein puncture are reliable surgical methods for children's totally implantable venous access port implantation. Surgeons should fully understand the complications of the venous access port, take measures to reduce the occurrence of complications, and properly handle the complications that have occurred.

[Clinical analysis of 30 cases of basal ganglia germinoma in children].

OBJECTIVE: To summarize and analyze the clinical characteristics of children with basal ganglia germinoma and to improve the level of early clinical diagnosis. METHODS: The clinical data of children diagnosed with basal ganglia germinoma admitted to the Pediatric Surgery Ward of Peking University First Hospital from January 2013 to December 2020 were retrospectively analyzed, and descriptive statistics were used to analyze the clinical characteristics of children with basal ganglia germinoma. RESULTS: A total of 30 patients were included in the study, 28 were male, 2 were female, the mean age at onset was (9.7±2.2) years, the median disease duration was 7 months, 27 had unilateral disease, and 3 had bilateral disease. The clinical manifestations were decreased limb muscle strength, cognitive function disorders, polydipsia, precocious puberty, intracranial hypertension, dysphonia and swallowing dysfunction. The serum and cerebrospinal fluid tumor marker alpha-fetoprotein (AFP) were normal in the 30 patients, and the serum and cerebrospinal fluid tumor marker ß-human chorionic gonadotropin (ß-HCG) were normal in 8 patients.The serum ß-HCG was normal in 11 patients but the cerebrospinal fluid ß-HCG was slightly elevated, and the serum and cerebrospinal fluid ß-HCG were slightly elevated in 11 patients. A total of 33 lesions with irregular shapes were found by imaging examination, including 15 (45.5%) patchy lesions, 10 (30.3%) patchy lesions, and 8 (24.2%) round-like high-density lesions. Tumors showed obvious high-density shadows on computed tomography (CT) scan. Magnetic resonance imaging (MRI) scan of the tumors showed low or isointensity on T1WI and isointensity on T2WI, accompanied by mild peritumoral edema, hemispheric atrophy, cerebral peduncle atrophy, calcification, cystic degeneration, ventricular dilatation and wallerian degeneration. On contrast-enhanced scans, the tumor showed no enhancement or heterogeneous enhancement. CONCLUSION: The main age of onset of germ cell tumors in the basal ganglia in children is about 10 years old, and males are absolutely dominant. The clinical features and imaging manifestations have certain characteristics. With both combined, the early diagnosis of germ cell tumors in the basal ganglia can be improved.

Bacillus velezensis WLYS23 strain possesses antagonistic activity against hybrid snakehead bacterial pathogens.

AIM: The aims of this study were to screen an antagonistic probiotic for the prevention and control of bacterial diseases in snakehead fish and to evaluate the antimicrobial activities, biosafety and biocontrol effect of the antagonistic strain. METHODS AND RESULTS: In this study, the WLYS23 strain exhibiting the most effective antagonistic properties against several fish pathogens was selected from the intestine of healthy snakehead fish. The strain was identified as Bacillus velezensis based on morphological, physiological and biochemical characteristics, and phylogenetic analysis. This strain showed amylase, cellulase, protease and lipase activities according to extracellular enzyme activity assays. Moreover, the cell-free extract of the WLYS23 strain exhibited strong antibacterial activity, with MICs of ≤64 µg ml-1 for most fish pathogens. Additionally, the cell-free extract was heat and pH stable, and resistant to protease, whereas their antimicrobial activities were significantly influenced by metal ions at high concentration. The WLYS23 strain and its cell-free extract were safe for snakehead and zebrafish. The disease resistance of snakehead fish was significantly increased following administration of the WLYS23 strain and its cell-free extract respectively. The complete genome of the WLYS23 strain was sequenced and found to harbour seven gene clusters encoding secondary metabolites with antimicrobial activity. CONCLUSION: The WLYS23 strain possesses great potential as a biocontrol agent, which can be commercially developed to improve disease control in freshwater aquaculture. SIGNIFICANCE AND IMPACT OF THE STUDY: Snakehead fish are important commercially farmed fish worldwide. However, the bacterial diseases caused by Aeromonas sp. and Nocardia seriolae in farmed snakehead fish lead to huge economic losses. Safe, economical and efficient probiotics are limited to prevent and control these diseases. Here, we provide a promising biocontrol agent with antagonistic activity against bacterial diseases of snakehead.

[Vincristine inhibits the proliferation of ovarian cancer cells by regulating the demethylation of RASSF2A].

Objective: To investigate the effect of vincristine on the proliferation of ovarian cancer cells by regulating RASSF2A demethylation. Methods: SKOV3 cells were infected with control (LV-NC) and RASSF2A lentivirus (LV-RASSF2A) and treated with or without vincristine. Cell counting kit-8 (CCK-8) was used to detect the activity of ovarian cancer cells (SKOV3) treated with different doses of vincristine. Colony formation assay was used to detect the proliferation of SKOV3 cells. Flow cytometry was used to detect the apoptosis of SKOV3 cells. Real time polymerase chain reaction (RT-PCR) was used to examine the mRNA expression of RASSF2A in IOSE-29 and SKOV3 cells. Western blot was used to examine the protein expression of RASSF2A in IOSE-29 and SKOV3 cells. Methylation-specific PCR was used to detect methylation and demethylation levels of RASSF2A gene in IOSE-29 and SKOV3 cells. Results: The cell viabilities of SKOV3 cell treated with 6.25 nmol/L, 12.5 nmol/L, 25 nmol/L, 50 nmol/L and 100 nmol/L vincristine were (87.19±4.49)%, (73.67±8.62)%, (66.35±6.04)%, (50.32±6.00)% and (34.92±6.11)%, respectively, lower than (100.46±4.69)% of control group (P<0.05). The half maximal inhibitory concentration of vincristine at 48 hours was 50.02 nmol/L. The proliferation abilities of SKOV3 cells in vincristine 12.5 nmol/L group, 25 nmol/L group and 50 nmol/L group were (41.70±2.21)%, (32.15±1.80)% and (23.00±2.01)%, respectively, significantly lower than (100.78±5.66)% in the control group (all P<0.05). The apoptotic rates of SKOV3 cells in vincristine 12.5 nmol/L group, 25 nmol/L group and 50 nmol/L group were (3.65±0.27)%, (5.21±0.76)% and (10.46±1.00)%, respectively, significantly higher than (2.12±0.23)% in the control group (all P<0.05). Compared with the IOSE-29 group (1.00±0.07 and 0.68±0.04), the mRNA expression (0.32±0.04) and protein expression (0.24±0.02) of RASSF2A were down-regulated in SKOV3 cells (P<0.05). Compared with the LV-NC group [(101.60±4.39)%, (100.73±3.29)%, (4.06±0.30)%], over-expression of RASSF2A down-requlated cell viability (68.92±3.94)%, inhibited proliferation (16.38±2.16)%, and promoted apoptosis (8.65±0.56)%, (P<0.05). Conclusion: Vincristine can increase RASSF2A expression and inhibit ovarian cancer cell proliferation by promoting the demethylation of RASSF2A promoter.

[Employment, turnover intention and the associated factors among public health graduates in China].

Objective: To understand the employment situation of graduates of public health-related majors and explore the associated factors of turnover intention among public health practitioners in China. Methods: In April 2020, the convenient sampling method was used to recruit public health related graduates from 98 universities with public health-related majors from 31 provinces in China (excluding Hong Kong, Macao and Taiwan) and from Chinese Center for Disease Control and Prevention (only including working or unemployed status, no requirement for graduation years). A total of 1 322 questionnaires were collected, of which 1 165 (88.1%) were valid. Through the network questionnaire survey, the information of public health graduates' work situation, job satisfaction and turnover intention were collected. Multivariate logistic regression model was used to analyze the associated factors of turnover intention, and structural equation model was constructed to explore the correlation between turnover intention and job satisfaction. Results: The age of 1 165 graduates was (28.1±4.8) years. Among them, 719 (61.7%) were female and 856 (73.5%) graduates were engaged in public health-related work after graduation. The results of multivariate logistic regression analysis showed that compared with those over 30 years old, graduates under 30 years old had higher turnover intention (OR=2.531, 95%CI: 1.549-4.155). Compared with those with junior or no title, graduates with senior title had higher turnover intention (OR=2.310, 95%CI: 1.047-5.162). The results of structural equation model analysis showed that the four factors of job satisfaction, 'salary and welfare', 'promotion development', 'work itself', and 'internal and external environment', were negatively correlated with turnover intention. The internal and external environment had the greatest impact on turnover intention (total effect =-0.539). Conclusion: Most graduates of public health-related majors are engaged in public health-related work in China. Age, professional title and job satisfaction are the associated factors of turnover intention.

[Therapeutic effect and clinical cost of multi-disciplinary team model of hepatoblastoma in children].

OBJECTIVE: To summarize and analyze the treatment process, long-term efficacy and clinical economics of children's hepatoblastoma (HB) in multi-disciplinary team (MDT) mode, so as to provide basis for the rational choice of diagnosis and treatment. METHODS: From January 2014 to February 2019, 13 cases of hepatoblastoma in children who completed the whole treatment course in the Pediatric Hematology Tumor Ward of Peking University First Hospital were collected and analyzed, and were followed up until June 30, 2020. There were 9 males and 4 females who were diagnosed and treated according to the MDT process in the hospital. The median age was 16 months (2-54 months), 69.23% (9/13) were under 2 years old. The characteristics, diagnosis and treatment process and treatment effect of the cases were summarized, and the cost of clinical treatment was analyzed. RESULTS: According to the pretreatment extent of disease(PRETEXT), there were 1, 9 and 3 children with stages Ⅱ, Ⅲ and Ⅳ. 76.92% (10/13) of the patients had the largest tumor diameter > 10 cm. All the patients received preoperative neoadjuvant chemotherapy (8 patients received 4 cycles of chemotherapy, and 6 patients changed the chemotherapy plan), surgical treatment and postoperative chemotherapy, the tumor volume decreased by more than 50% (64%-95%) in 12 cases, except 1 case with no significant increase of alpha fetal protein and multiple lesions.The median length of stay was 87 days (68-214 days), the median cost of stay was 200 000 yuan (115 000-500 000 yuan), the median length of stay was 7 days (5-17 days), the median cost of stay was 20 000 yuan (15 000-60 000 yuan), and the incidence of postoperative complications was 7.69% (1/13). All the patients were followed up for 16-69 months. All the patients survived. CONCLUSION: Under the MDT mode, the treatment is seamless connection, the long-term prognosis of children with HB is good, and the total hospitalization cost and time are within the acceptable range. Standard preoperative neoadjuvant chemotherapy can significantly reduce the tumor, improve the resection rate, reduce postoperative complications, reduce the total individual expenditure, shorten the total hospital stay, and further improve the long-term disease-free survival rate.

[Effects of alprostadil in ß-aminopropanitrile induced aortic dissection in a murine model].

Objective: To investigate the protective role of alprostadil on aortic dissection. Methods: 26 C57BL6 male mice were divided into control group (normal drinking water, n=13) and model group (1 g·kg-1·d-1 BAPN via drinking water, n=13). On day 14, mRNA expression of inflammatory-related genes as well as EP receptor families were detected by RT-PCR (n=6 each) and EP4 protein levels were determined by Western blot (n=7 each). Another 88 mice were divided into 3 groups: control group (n=22), model group (n=33) and treatment group (n=33). The mice in model group and treatment group were applied with BAPN (1 g·kg-1·d-1) via drinking water. The mice in treatment group received additional intraperitoneal injection with alprostadil (80 µg·kg-1·d-1) for 28 days. The mice in the control and model group received equal volume intraperitoneal injection with 0.9% saline respectively. The body weight and systolic blood pressure, the mortality and morbidity were monitored from the beginning until the designed end of the study. On day 28, the mice were sacrificed and aorta were fixed, embedded and sliced, followed by staining with HE and Victoria Blue. The distribution of EP4 was determined by immunohistochemistry in control (n=6) and model group (n=6). Furthermore, the concentration of PGE1 were tested among model (n=3) and treatment group (n=4). EP4 protein expression was determined in model group (n=7) and treatment group (n=6). Results: On day 14, mRNA expression level of MCP-1 ((2.74±1.55) vs. (1.00±0.49),<0.05) and MMP2((1.38±0.42) vs. (1.00±0.27), P<0.05) was significantly upregulated in model group compared with control group. Protein expression of EP4 receptor also increased in aorta in model group compared with control group (1.48±0.51 vs. 1.00±0.19, P<0.05). In the dissection area, the EP4 expression was also enriched compared with non-dissection area, particularly in endothelial cells and inflammatory cells on day 28. BAPN applied in drinking water (model and treatment groups) successfully induced the aortic dissection in mice, some mice died of the rupture. The elastic fibers were fractured, and the infiltrated immune cells were visible in dissected tissue. False lumen was formed. There was no dissection and death in the control group. Compared with control group, the morbidity and mortality rates were significantly increased in the model group (60.6%, 20/33, 30.3%, 10/33) and the treatment group (72.7%, 24/33, 24.2%, 8/33). The mortality and morbidity rates were similar between model and treatment groups. There is no difference in terms of SBP among three groups (P>0.05). Further study showed that after alprostadil injection, the blood concentration of PGE1 was increased in treatment group ((0.540±0.041 vs. 0.436±0.012)µmol/L, P<0.05). Besides, the EP4 receptor expression was downregulated in the treatment group compared to model group (0.60±0.30 vs. 1.00±0.20, P<0.05). Conclusion: EP4 expression is upregulated in BAPN induced aortic dissection mouse model. No protective effects are observed post alprostadil treatment in this model probably due to the reduced expression of EP4.

Au nanorod-coupled microfiber optical humidity sensors.

We demonstrate a high-sensitivity relative humidity (RH) sensor taking advantage of single-band narrow plasmon resonance of a single Au nanorod coupled to a whispering gallery cavity mode of a polyacrylamide microfiber. From the resonance peak shift, the sensor could achieve a sensitivity up to 0.51 nm/% RH with a cavity size of about 2 µm. By coupling multiple Au nanorods along the microfiber axis, we demonstrate a position-dependent microfiber optical humidity sensor with a 1.5-mm spatial resolution, which can be potentially reduced to micrometer level, paving a way toward high-resolution distributed microfiber optical sensors.

[High definition MRI rectal lymph node aided diagnostic system based on deep neural network].

Objective: To investigate the clinical significance of high definition (HD) MRI rectal lymph node aided diagnostic system based on deep neural network. Methods: The research selected 301 patients with rectal cancer who underwent pelvic HD MRI and reported pelvic lymph node metastasis from July 2016 to December 2017 in Affiliated Hospital of Qingdao University. According to the chronological order, the first 201 cases were used as learning group. The remaining 100 cases were used as verification group. There were 149 males (74.1%) and 52 females in the study group, with an average age of 58.8 years. There were 76 males (76.0%) and 24 females in the validation group, with an average age of 60.2 years. Firstly, Using deep learning technique, researchers trained the 12 060 HD MRI lymph nodes images data of learning group with convolution neural network to simulate the judgment process of radiologists, and established an artificial intelligence automatic recognition system for metastatic lymph nodes of rectal cancer. Then, 6 030 images of the validation group were clinically validated. Artificial intelligence and radiologists simultaneously diagnosed all cases of HD MRI images and made the diagnosis results of metastatic lymph node. Receiver operating characteristic (ROC) curve and area under curve (AUC) were used to compare the diagnostic level of them. Results: After continuous iteration training of the learning group data, the loss function value of artificial intelligence decreased continuously, and the diagnostic error decreased continuously. Among the 6 030 images of verification group, 912 images were considered to exist metastatic lymph nodes in radiologists' diagnosis and 987 in artificial intelligence diagnosis. There were 772 images having identical diagnostic results of lymph node location and number of metastases with the two methods. Compared with manual diagnosis, the AUC of the intelligent platform was 0.886 2, the diagnostic time of a single case was 10 s, but the average diagnostic time of doctors was 600 s. Conclusion: The HD MRI lymph node automatic recognition system based on deep neural network has high accuracy and high efficiency, and has the clinical significance of auxiliary diagnosis.

[Tanshinoneâ ¡A attenuates carotid artery atherosclerosis by deactivating mast cells in adventitia].

Objective: To investigate the effects of tanshinone ⅡA on atherosclerosis plaque formation and adventitial mast cells activation in high-fat-diet induced Apo E(-/-) mice model. Methods: Sixteen 8-week-old Apo E(-/-)male mice and eight 8-week-old C57BL/6 male mice were randomly allocated into following group: the control group (C57BL/6 + carboxymethyl cellulose per gavage), the atherogenic group (Apo E(-/-)+carboxymethyl cellulose per gavage) and the tanshinoneⅡA intervention group (Apo E(-/-)+30 mg/kg tanshinone ⅡA per gavage). All three groups were fed with high-fat-diet for 26 weeks. Tanshinone ⅡA/carboxymethyl cellulose was applied by the method of gavage administration 6 weeks before execution. After 26 weeks, tumor necrosis factor-α (TNF-α) andinterleukin (IL)-6 levels in serum were assessed by ELISA. Carotid artery was removed, fixed with paraformaldehyde, embedded with paraffin and sectioned. Percentage of stenosis was evaluated on HE stained sections. Plaque progression was assessed by Movat staining. Toluidine blue staining was used to evaluate mast cells infiltration and activation. Immunochemistry staining was used to assess 5-HT, TNF-α and IL-6 expression. mRNA expression of mast cell marker Fcer1a in adventitial tissue was detected by real time-PCR. Results: After high-fat-diet for 26 weeks, the mice in the atherogenic group showed advanced atherosclerosis, tanshinoneⅡA intervention reduced the percentage of carotid artery stenosis caused by atherosclerotic plaque formation ((58.48±8.07)% vs. (80.31±4.08)%, P<0.05). Compared with the atherogenic group, tanshinone ⅡA intervention group had lower level of TNF-α ((12.39±1.62)pg/ml vs. (17.44±1.42)pg/ml) and IL-6 ((116.24±12.16)pg/ml vs. (166.05±19.09)pg/ml) in serum, lower TNF-α ((20 145±1 556) vs. (25 288±1 671)) and IL-6 ((25 688±1 604) vs. (35 286±4 198)) expression in adventitia (all P<0.05). TanshinoneⅡA intervention also decreased the number of mast cells infiltration and activation, reduced 5-HT expression and mast cell marker Fcer1a mRNA relative expression in adventitia (all P<0.05). Conclusions: Tanshinone ⅡA could attenuate induced by high-fat-diet carotid artery atherosclerosis in Apo E(-/-) mice. The protective effect of tanshinoneⅡA is probably mediated through reducing the number and activation percentage of mast cells, decreasing the release of inflammatory cytokines and inflammation of carotid artery in adventitia.

[Interleukin-1ß and C-reactive protein level in plasma and gingival crevicular fluid in adolescents with diabetes mellitus].

OBJECTIVE: Cytokines produced by various cells are strong local mediators of inflammation. Interleukin-1beta (IL-1ß) and C-reactive protein (CRP) play essential roles in the development and progression of diabetes mellitus (DM). Thus periodontal diseases could be related to DM via the same mediators of inflammation. To evaluate plasma and gingival crevicular fluid (GCF) levels of IL-1ß and CRP in adolescents with DM to further investigate whether DM has an impact on the levels of inflammation factors at an early stage, and to analyze the risk of developing periodontal diseases in adolescents with DM. METHODS: A total of 121 adolescents aged from ten to sixteen years were enrolled, 41 adolescents diagnosed with diabetes mellitus were collected in the DM group, and 80 nondiabetic adolescents as the control group. The periodontal indices of each individual were recorded, including plaque index (PLI), modified bleeding index (mBI), probing depth (PD) and attachment loss (AL). GCF and intravenous blood samples were collected, and CRP and IL-1ß levels were detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: (1) PLI of DM group and control group were 1.23±0.05 and 0.95±0.04 separately, with significant difference (P=0.001). DM group and control group had mBI of 0.80±0.08 and 0.51±0.06 separately, with significant difference (P=0.003). Attachment loss was found in none of the subjects. PDs of DM group and control group were (2.37±0.51) mm and (2.31±0.05) mm separately, and there was no significant difference. (2) CRP in GCF was only detectable in partial of the individuals, with a detectable rate of 22.9% (11/48) in total. The detectable rate of CRP in GCF was significantly higher in DM group (38.5%) than that in control group (4.5%, P=0.006). The plasma level of CRP in DM group [0.23 (0.15, 1.89) mg/L] was higher than that in control group [0.19 (0.12, 4.18) mg/L], but without significance (P=0.776). (3) The plasma levels of IL-1ß in DM group and control group were (14.11±0.57) ng/L and (14.71±0.50) ng/L separately, but there was no significance (P=0.456). GCF levels of IL-1ß in DM group and control group were (12.91±1.95) µg/L and (17.68±3.07) µg/L, without significant difference (P=0.185). CONCLUSION: Periodontitis was not observed in adolescents with DM at an early stage. However, the rising levels of periodontal indices and CRP in GCF, might indicate that adolescents with DM have a higher risk of developing periodontal diseases in the future.

[Establishment of ß-aminopropionitrile-induced aortic dissection model in C57Bl/6J mice].

Objective: To establish the mouse aorta dissection (AD) model through drinking water containing ß-aminopropionitrile (BAPN). Methods: Forty 3-week-old C57B1/6J male mice were divided into four groups according to randomized block design: control, 0.2, 0.4 and 0.8 g·kg(-1)·d(-1) BAPN groups (dissolving respective dose of BAPN in the drinking water, n=10 each group). Arterial systolic blood pressure and heart rate were measured weekly in conscious, restrained mice using a noninvasive computerized tail-cuff system. Mice those died of rupture of aortic dissecting aneurysm during the study were autopsied and the aorta was examined. After 4 weeks, survived mice were sacrificed by an overdose of sodium pentobarbital and the whole aorta was harvested and analyzed. Results: The incidence of AD and the mortality of ruptured AD was 0 and 0 in control group, 30% (3/10) and 20% (2/10) in 0.2 g·kg(-1)·d(-1) BAPN group, 50% (5/10) and 40% (4/10) in 0.4 g·kg(-1)·d(-1) BAPN group, 90% (9/10) and 70% (7/10) in 0.8 g·kg(-1)·d(-1) BAPN group (both P<0.05 vs. control group). The incidence of AD and the mortality of ruptured AD increased in proportion to BAPN concentration increase. In 0.8 g·kg(-1)·d(-1) BAPN group, 7 mice died of dissecting aneurysm rupture during the experiment, among which 5 dissecting aneurysms were mainly located in the thoracic aorta and 2 dissecting aneurysms in abdominal aorta. The diameters of thoracic aorta and abdominal aorta were (1.38±0.19) and (1.23±0.13) mm in control group, (2.43±1.56) and (1.30±0.26) mm in 0.2 g·kg(-1)·d(-1) BAPN group, (2.45±1.28) and (1.30±0.31) mm in 0.4 g·kg(-1)·d(-1) BAPN group, (2.87±0.57) and (1.95±0.81) mm in 0.8 g·kg(-1)·d(-1) BAPN group (both P<0.05 vs. control group). The diameters of thoracic aorta and abdominal aorta in mice also increased in proportion with BAPN concentration increase. Furthermore, blood-filled false lumen formation and elastic fibers fragmentation were evidenced in hematoxylin-eosin stained and Vitoria blue-Sirius red stained aortic cross-sections of mice in the 0.8 g·kg(-1)·d(-1) BAPN group. Conclusion: BAPN treatment induced aortic dissection model in C57Bl/6J mice can serve as a useful wild-type mouse model for the mechanism and pharmaceutical studies of AD.

[The lesser omentum approach for laparoscopic pancreatic enucleation].

Objective: To evaluate the feasibility and strategy of the lesser omentum approach for laparoscopic pancreatic enucleation. Methods: Between June 2011 and October 2013, 6 laparoscopic pancreatic enucleations were performed by lesser omentum approach.The average age was 42 years, including 1 male and 5 female.The preoperation diagnosis of 6 cases were pancreatic islet cell tumors determined by abdominal CT/MRI, ultrasound and digital subtraction angiography.The tumors of 3 cases located in pancreatic neck, 2 tumors located in neck and body of pancreas, and 1 tumor located in pancreatic body.Their biggest tumor diameter were 0.8-2.5 cm. Results: Among the 6 cases, all laparoscopic pancreatic enucleations were successfully performed.None of the patients were converted to open operation.Eestimated blood loss was (26.7±18.6)ml, operating time was (82.5±19.4)minutes, and postoperative length of stay was (5.17±1.17)days.Additionally, postoperative complication included grade A pancreatic fistula in 1 case.After 36-64 months followed-up, there was no tumor recurrence and clinical symptom disappeared. Conclusion: For the islet cell tumors located in pancreatic neck and body, the lesser omentumapproach may contribute to good surgical view and operative space, which can make pancreatectomy safer and easier for clinical application.

Psychological and cognitive impairment of long-term migrators to high altitudes and the relationship to physiological and biochemical changes.

BACKGROUND AND PURPOSE: The present study aimed to examine how long-term migration to high-altitude regions affects mentality and cognition, and the correlation with various physiological and biochemical changes. METHODS: The WHO Neurobehavioral Core Test Battery, Raven's Standard Progressive Matrices (RSPM) and Pittsburgh Sleep Quality Index questionnaire were used to assess 141 young male subjects who lived in plain regions and 217 young male subjects who had migrated to a 4500 m high-altitude region and lived there for 1-5 years. Arterial oxyhemoglobin saturation, cerebral tissue oxygenation indices (TOIs), serum S100B and brain-derived neurotrophic factor (BDNF) were also measured. RESULTS: Long-term migrators to a high-altitude region exhibited exacerbated mood disorders, retarded color discrimination ability, decreased visual memory capacity, and impaired perceptual motor skill and motion stability. In addition, the migrators exhibited lower RSPM scores and lower sleep quality. Further analyses revealed significant correlations between sleep quality and cerebral TOIs, mood and sleep quality, mood and certain cognitive functions, mood and serum BDNF levels, and RSPM scores and serum S100B levels. CONCLUSIONS: Long-term living at high altitudes causes significant impairment of psychological and cognitive function. Cerebral hypoxic extent, sleep quality and biochemical dysfunction are major influencing factors.

Correlation and the mechanism of lithium ion diffusion with the crystal structure of Li7La3Zr2O12 revealed by an internal friction technique.

The correlation and transport mechanism of lithium ions with the crystal structure of a fast lithium ion conductor Li7La3Zr2O12 are mainly investigated by internal friction (IF) and AC impedance spectroscopy techniques. Compared with the poor conductivity of tetragonal Li7La3Zr2O12, the Al stabilized cubic phase exhibits a good ionic conductivity that can be up to 1.9 × 10(-4) S cm(-1) at room temperature, which can be ascribed to the disordered distribution of lithium ions in the cubic phase. A well-pronounced relaxation IF peak (labeled as peak PC) is observed in the cubic phase while a very weak IF peak (labeled as PT) is observed in the tetragonal phase, further evidencing the difference in lithium ion migration in the two phases. Peak PC can be decomposed into two sub-peaks with the activation energy and the pre-exponential factor of relaxation time being E1 = 0.41 eV and τ01 = 1.2 × 10(-14) s for the lower temperature peak PC1 and E2 = 0.35 eV and τ02 = 1.9 × 10(-15) s for the higher temperature PC2 peak, respectively. Based on the crystalline structure of a cubic garnet-type Li7La3Zr2O12 compound, an atomistic mechanism of lithium ion diffusion via vacancies is suggested, i.e. 48g(96h) ↔ 48g(96h) for peak PC1 and 48g(96h) ↔ 24d for peak PC2, respectively. The weak PT peak in the tetragonal phase is preliminarily interpreted as due to the short jump process among neighboring octahedral sites and vacant tetrahedral sites.

Influence of the c.1517G>C genetic variant in the XRCC1 gene on pancreatic cancer susceptibility in a Chinese population.

We investigated the influence of the c.1517G>C genetic variant in the X-ray repair complementing group 1 gene (XRCC1) on pancreatic cancer (PC) susceptibility in Chinese patients. A total of 390 PC patients and 392 controls were enrolled in this case-control study. The genotypes of c.1517G>C genetic variants were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Our findings suggested that the allele and genotype frequencies in PC patients were significantly different from those in cancer-free controls. The CC genotype was associated with an increased risk of PC compared to the wild-type GG genotype (odds ratio=2.43, 95% confidence interval 1.43-4.13, X2=11.19, P=0.001). The C allele may contribute to the development of PC (C vs G, odds ratio=1.32, 95% confidence interval 1.06-1.64, X2=6.25, P=0.012). Results from this study indicate that the c.1517G>C genetic variant of the XRCC1 gene is significantly associated with PC susceptibility in the Chinese population.

Borrowed dislocations for ductility in ceramics.

The inherent brittleness of ceramics, primarily due to restricted atomic motions from rigid ionic or covalent bonded structures, is a persistent challenge. This characteristic hinders dislocation nucleation in ceramics, thereby impeding the enhancement of plasticity through a dislocation-engineering strategy commonly used in metals. Finding a strategy that continuously generates dislocations within ceramics may enhance plasticity. Here, we propose a "borrowing-dislocations" strategy that uses a tailored interfacial structure with well-ordered bonds. Such an approach enables ceramics to have greatly improved tensile ductility by mobilizing a considerable number of dislocations in ceramic borrowed from metal through the interface, thereby overcoming the challenge associated with direct dislocation nucleation within ceramics. This strategy provides a way to enhance tensile ductility in ceramics.

Effect of earthworm loads on organic matter and nutrient removal efficiencies in synthetic domestic wastewater, and on bacterial community structure and diversity in vermifiltration.

In this paper, we studied the effect of earthworm loads on the removal rates of chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total nitrogen, and total phosphorus from synthetic domestic sewage and on the bacterial community structure and diversity of substrates in earthworm packing beds. The different vermifiltrations (VFs), including the control, are successful in removing both organic matter (OM) and nutrients. The removal rate of NH3-N at 12.5 g of earthworm/L of soil VF is higher compared with that at 0 and 4.5 earthworm load VFs. The highest Shannon index, in the earthworm packing bed, occurred at 16.5 earthworm load VF. Furthermore, the COD removal rate is significantly correlated with the Shannon index, which reveals that OM removal for synthetic domestic sewage treatment at VF might be more dependent on bacterial diversity at the earthworm packing bed. The band distributions and diversities of the bacterial community for samples from different earthworm loads in VFs suggest that the bacterial community structure was only affected within the earthworm packing bed when the earthworm load reached a certain level. The present study adds to the current understanding of OM and nutrient degradation processes in VF domestic wastewater treatment.

[Research advances of natural biomaterials in promoting wound repair].

Acute and chronic wounds seriously threaten patients' life health and quality of life, therefore, wound repair has become a hot topic of research for scholars at home and abroad in recent years. With the development of material science and tissue engineering, more and more biomaterials prepared from natural ingredients were used in basic research and clinical treatment of wound repair. Such biomaterials can be used as templates for wound tissue regeneration to induce autologous cell adhesion and migration, and promote the deposition of extracellular matrix, which have broad clinical application prospects. This paper reviews the characteristics and application advance of natural biomaterials which are popular in the field of wound repair, aiming to provide ideas for the research and development of new wound dressing and tissue engineering skin.

Non-equilibrium umbrella sampling applied to force spectroscopy of soft matter.

Physical systems often respond on a timescale which is longer than that of the measurement. This is particularly true in soft matter where direct experimental measurement, for example in force spectroscopy, drives the soft system out of equilibrium and provides a non-equilibrium measure. Here we demonstrate experimentally for the first time that equilibrium physical quantities (such as the mean square displacement) can be obtained from non-equilibrium measurements via umbrella sampling. Our model experimental system is a bead fluctuating in a time-varying optical trap. We also show this for simulated force spectroscopy on a complex soft molecule--a piston-rotaxane.