Resistance to Sunk Cost Propensity Moderate Relationship between Negative Life Event and Hopelessness.

Previous research has found that a negative life event is a main risk factor for hopelessness, which in turn is considered to be a proximal cause of major depression disorder and a suicide risk factor. Unfortunately, very little attention has been paid to the role of decision-making constructs between negative life events and hopelessness. To fill this gap, the present study aims to test the moderation role of sunk cost propensity in this relationship, which is an over-generalized tendency to persist, based on past investment. A total of 495 university students completed assessment of their resistance to sunk cost propensity, whereas the negative life events, hopelessness, mental health state (depression, anxiety) and big-five personality traits were measured by various questionnaires. Participants' tendency to resist sunk cost propensity moderated the relationship between negative life events and hopelessness. Individuals who tended to resist sunk cost bias are more vulnerable to the adverse effects of negative life events. This effect is still significant, even after controlling for individuals' psychological well-being (depression, anxiety) and big-five personality traits. The current findings provide preliminary evidence that resistance to sunk cost propensity may be an important characteristic associated with an individual's hopelessness when exposed to a negative life event.

Antifriction Mechanism of Longitudinal Vibration-Assisted Insertion in DBS.

Deep brain stimulation (DBS) is an effective treatment for Parkinson's disease. The insertion of brain tissue is an important procedure that affects the whole operation and the sequela. During the insertion process, the friction between the tissue and the needle shaft is the main factor affecting the degree of tissue damage and the accuracy of target location. Vibration-assisted needle insertion has been shown to reduce friction during needle insertion into biological tissue. LuGre model is a friction model that includes coulomb friction and viscous friction between two contact surfaces and accurately describes the Stribeck effect. This paper studies the influence of longitudinal vibration on the friction force during needle insertion. Based on LuGre model, the influence of longitudinal vibration parameters on friction force is discussed. Through experiments on porcine brain tissue and gel phantom, the friction force during insertion and the positive pressure of tissue against the needle under different vibration parameters were investigated. The experiment showed that the vibration can change the friction force by affecting the equivalent friction coefficient and the positive pressure of tissue against the needle. The equivalent friction coefficient showed a specific trend with the change of vibration parameters, while the positive pressure does not change with the vibration parameters.

Effect of vibration frequency on frictional resistance of brain tissue during vibration-assisted needle insertion.

Deep brain stimulation (DBS) is an effective treatment for Parkinson's disease. The cannula insertion process plays an important role in DBS. The friction force during needle insertion influences the precision of the insertion and the degree of damage to the brain tissue. This paper proposes a method of longitudinal vibration assisted insertion to reduce the friction during insertion and improve the effects of the insertion. Cannulas were inserted into twenty eight pig brains at multiple frequencies and fixed amplitudes, and the resulting friction force was measured. On this basis, the LuGre model was used to analyze the friction force trend under vibration-assisted conditions. The frictional forces of vibration-assisted insertion with frequencies ranging from 200-1200 Hz and an amplitude of 1 µm were measured. The results show that the friction between the needle shaft and the tissue is smaller with vibration than without vibration. In this experiment, the friction is reduced by up to 24.43%. The friction force trend of vibration-assisted insertion conforms to the simulation results of the LuGre model.

Aquamicrobium soli sp. nov., a bacterium isolated from a chlorobenzoate-contaminated soil.

An aerobic, Gram-stain negative, short rod-shaped, asporogenous, non-motile bacterium designated strain NK8T was isolated from a chlorobenzoate contaminated soil in China. Strain NK8T was observed to grow optimally at pH 7.0, 30 °C and in the absence of NaCl in LB medium. The G + C content of the total DNA of strain NK8T was found to be 65.5 mol%. The 16S rRNA gene sequence of strain NK8T showed high similarity to that of Aquamicrobium aerolatum Sa14T (97.3%), followed by Aquamicrobium lusatiense S1T (96.7%) and Mesorhizobium sangali SCAU7T (96.6%). The DNA-DNA relatedness between strain NK8T and A. aerolatum Sa14T was 35.5 ± 0.9%. The major fatty acids of strain NK8T were determined to be C19:0 cyclo ω8c (45.6%), C18:1 ω7c (33.4%) and C16:0 (8.4%). The respiratory quinone was found to be ubiquinone Q-10. The major polyamine was found to be spermidine. The polar lipid profile include the major compounds phosphatidylcholine and diphosphatidylglycerol, and moderate amounts of phosphatidylethanolamine, phosphatidylmonomethylethanolamine, aminolipid and phospholipid. Based on the differential biochemical and physiological characteristics, the geno-, chemo- and phenotypic characteristics, strain NK8T is proposed to represent a novel species of the genus Aquamicrobium, Aquamicrobium soli sp. nov. The type strain is NK8T (=KCTC 52165T=CCTCC AB2016045T).

[Liver histopathological features influencing HBeAg seroconversion in patients with HBeAg-positive chronic hepatitis B responding to Peg-IFN treatment].

OBJECTIVE: To investigate the therapeutic efficiency of antiviral treatment with pegylated-interferon (Peg-IFN) for hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) and to explore whether liver histopathological features or other factors influence the HBeAg seroconversion treatment response. METHODS: Eighty HBeAg-positive CHB patients with diagnosis confirmed by liver puncture were treated with Peg-IFN(2a or 2b)body weight dose, once weekly). At treatment week 48, the rate of HBeAg seroconversion was determined and used to analyze the influence of liver histopathological features (liver biopsy assessment of: inflammation, graded G0 to G4; fibrosis stage, graded S0 to S4), sex, age, differential levels (pre-treatment baseline vs. week 48 post-treatment) of serum alanine transferase (ALT), and HBV DNA, by binary logistic analysis. RESULTS: At week 48, the overall rate of HBeAg seroconversion was 30.0%. The rate of HBeAg seroconversion gradually advanced with increased liver inflammation (X2 = 8.435, P = 0.015): 9.09% of the 22 patients with G1; 31.58% of the 38 patients with G2; 47.30% of the 19 patients with G3; the one patient with G4. In contrast, the rate of HBeAg seroconversion showed a much weaker association with liver fibrosis (X2 = 5.917, P = 0.116). Only baseline HBeAg level, and no other baseline index, was significantly different between the patients who achieved HBeAg seroconversion and those who did not. Liver inflammation and baseline HBeAg level were identified as influencing factors of HbeAg seroconversion in response to Peg-IFN treatment. CONCLUSION: Peg-IFN therapy induces a higher rate of HBeAg seroconversion in HBeAg-positive CHB patients with severe liver inflammation; histological analysis of pre-treatment liver biopsies may help to identify patients most likely to benefit from the antiviral regimen.

Molecular characterization of the enzymes involved in the degradation of a brominated aromatic herbicide.

Dehalogenation is the key step in the degradation of halogenated aromatics, while reductive dehalogenation is originally thought to rarely occur in aerobes. In this study, an aerobic strain of Comamonas sp. 7D-2 was shown to degrade the brominated aromatic herbicide bromoxynil completely and release two equivalents of bromides under aerobic conditions. The enzymes involved in the degradation of bromoxynil to 4-carboxy-2-hydroxymuconate-6-semialdehyde, including nitrilase, reductive dehalogenase (BhbA), 4-hydroxybenzoate 3-monooxygenase and protocatechuate 4,5-dioxygenase, were molecularly characterized. The novel dehalogenase BhbA was shown to be a complex of a respiration-linked reductive dehalogenase (RdhA) domain and a NAD(P)H-dependent oxidoreductase domain and to have key features of anaerobic respiratory RdhAs, including two predicted binding motifs for [4Fe-4S] clusters and a close association with a hydrophobic membrane protein (BhbB). BhbB was confirmed to anchor BhbA to the membrane. BhbA was partially purified and found to use NAD(P)H as electron donors. Full-length bhbA homologues were found almost exclusively in marine aerobic proteobacteria, suggesting that reductive dehalogenation occurs extensively in aerobes and that bhbA is horizontally transferred from marine microorganisms. The discovery of a functional reductive dehalogenase and ring-cleavage oxygenases in an aerobe opens up possibilities for basic research as well as the potential application for bioremediation.

Detecting carcinoma cells in peripheral blood of patients with hepatocellular carcinoma by immunomagnetic beads and rt-PCR.

BACKGROUND: Increasing the sensitivity and specificity of detecting circulating carcinoma cells of patients with hepatocellular carcinoma (HCC) is very important for monitoring recurrence. GOAL: To establish a novel method of detecting circulating carcinoma cells. STUDY: For method development, 3 sets of controls using HCC cell line HepG2 cells were used. (A): Serial dilutions of HepG2 cells were directly used to extract total RNA for nested reverse transcription-polymerase chain reaction (RT-PCR). (B): Five milliliter of healthy blood was spiked with a serial dilution of HepG2 cells and was used for Ficoll density gradient centrifugation to recover cells. The cells were used to extract total RNA for RT-PCR. (C): After cell recovery with the same procedure as B, the cells were sorted sequentially by CD45 and Ber-EP4 immunomagnetic beads and used for RNA extraction and RT-PCR. For clinical samples, 44 patients with HCC and 7 healthy subjects were included. The alpha-fetoprotein mRNA was amplified using nested RT-PCR technique. RESULTS: The spiking experiments using HepG2 cells showed that 10 cells in 5 mL blood could be detected by method C and an excellent dose-response to the number of spiked cells. Whereas, method B lacked any dose-response and would yield high false-positive rates. In clinical samples, the improved method led to a positive detection rate of 52.9%, 76.9%, and 92.9% in Child-Plug class A, B, and C, respectively. There was significant difference between class A and class C (P<0.05). The total positive detection rate was 72.7%. CONCLUSIONS: Combining negative and positive immunomagnetic beads with RT-PCR technique may improve the sensitivity and specificity of detecting circulating HCC cells.

Detecting AFP mRNA in peripheral blood of the patients with hepatocellular carcinoma, liver cirrhosis and hepatitis.

BACKGROUND: The low frequency of disseminated carcinoma cells in the blood now makes immunomagnetic bead sorting and reverse transcriptase-polymerase chain reaction (RT-PCR) technique more popular. METHODS: Three milliliters of peripheral blood were collected from 91 patients and 18 normal donors. The circulating carcinoma cells were enriched with CD45 and Ber-EP4 immunomagnetic beads. The alpha-fetoprotein (AFP) mRNA was amplified with nested RT-PCR. RESULTS: The total positive detection rate was 72.1%, 43.8%, 25.0%, 100%, and 66.7% in patients with hepatocellular carcinoma (HCC) untreated, liver cirrhosis (LC), hepatitis, metastasis liver cancer, and postsurgery of hepatocellular carcinoma, respectively. There was a significant difference among the patients with HCC, LC and hepatitis (HCC vs. LC, P<0.05; HCC vs. hepatitis, P<0.01) and between Class A and B of the HCC patients (P<0.05). Meanwhile, AFP mRNA was markedly expressed in HCC patients compared to the patients with no HCC (LC and hepatitis). The levels of aspartate transaminase (AST) and gamma-glutamyltranspeptidase (GGT) were significantly different in AFP mRNA-positive patients with autoimmune chronic active hepatitis B (CAHB) or LC in contrast to the corresponding negative patients. CONCLUSION: Combining negative and positive immunomagnetic bead sorting and RT-PCR technique can effectively detect circulating tumor cells. AFP mRNA is a more reliable marker of metastasis compared to serum AFP.