Theoretical Study on Ethylamine Dissociation Reactions Using VRC-VTST and SS-QRRK Methods.

Barrierless bond dissociation reactions play an important role in fuel combustion. In this work, the pressure-dependent dissociation rate constants of ethylamine (EA) are accurately determined using variable-reaction-coordinate variational transition-state theory combined with the system-specific quantum Rice-Ramsperger-Kassel method. Before the kinetics calculations, the performances of four density functional theory methods in describing the bond dissociation of EA are evaluated against the benchmark method, FIC-MRCISD(T)+Q/cc-pVTZ, and the MN15-L/cc-pVTZ method is the best choice. By comparison of the Gibbs free energies and the rate constants for the bond dissociation reactions of EA, ethanol, and propane, the influence of functional groups on the reaction kinetics is discussed. The kinetics calculations show that the dissociation rate constants of EA are sensitive to pressure at low pressures and high temperatures, and the dominant channel is the reaction that yields C2H5 and NH2 radicals. A literature combustion model of EA is updated with our calculations, and the satisfactory agreement between the model predictions and reported ignition delay times of EA suggests the reliability of our calculations.

[The relationships between functional gastrointestinal diseases and psychological factors, diet and lifestyles: a network analysis].

Objective: To investigate the relationship between common functional gastrointestinal diseases symptoms with psychological factors, diet and lifestyles by using the network analysis method which has achieved great success in the field of psychology in recent years. Method: A questionnaire survey was conducted in two military units using the cluster sampling method during July 2020, and a total of 1 805 subjects were included. Functional gastrointestinal disease symptoms were evaluated with the Gastrointestinal Symptom Rating Scale (GSRS). The state, trait anxiety scale and stress response scale were used to evaluate the mental and psychological state by self-evaluation. R was used to build the network and calculate statistical parameters. Results: 1 486 of the 1 805 subjects (82.3%) had experienced functional gastrointestinal diseases symptoms within 2 weeks, but most of them were mild. Network analysis shows that there was a strong interaction between digestive system symptoms with different clinical manifestations (Spearman coefficient ranges 0.31-0.56). There was a clear relationship between functional gastrointestinal symptoms and mental and psychological factors (Spearman coefficient ranges 0.16-0.27), but there was no clear interaction with diet, age, education level, body mass index, etc. Functional gastrointestinal diseases symptoms were connected with mental and psychological factors through two nodes: stress and indigestion. The stability coefficient of node strength correlation was 0.75, indicating that the network was stable. Conclusions: The current study revealed the network structure and features of functional gastrointestinal diseases symptoms with mental and psychological factors. The key linking nodes provided potential interfering target for controlling functional gastrointestinal symptoms related to mental and psychological factors.

[Study of the effects of long-term outcomes of autologous peripheral blood stem cell reinfusion in patients with decompensated cirrhosis].

Objective: Autologous peripheral blood stem cells (PBSC) derived from bone marrow can promote liver regeneration and improve the liver function of patients, but there are few studies on its effect on the long-term outcomes in patients with decompensated cirrhosis. Based on previous work, this study observed the clinical outcomes of PBSC treatment in patients with decompensated cirrhosis for 10 years, in order to provide more data support for the safety and efficacy of stem cells in clinical applications. Methods: Data of patients with decompensated liver cirrhosis who completed PBSC treatment in the Department of Gastroenterology of the First Affiliated Hospital of Air Force Military Medical University from August 2005 to February 2012 were included. The follow-up endpoint was death or liver transplantation, and patients who did not reach the follow-up endpoint were followed-up for at least 10 years. The patients with decompensated liver cirrhosis who met the conditions for PBSC treatment but did not receive PBSC treatment in our hospital during the same period were used as controls. Results: A total of 287 cases with decompensated liver cirrhosis had completed PBSC treatment, and 90 cases were lost to follow-up within 10 years after surgery. A total of 151 cases with complete survival follow-up data were included in the control group. There were no statistically significant differences in baseline information such as gender, age, etiological composition and liver function score between the two groups. The 10-year survival rate was higher in PBSC than control group (37.56% vs. 26.49%, P<0.05). Cholinesterase, albumin, international normalized ratio, Child-Turcotte-Pugh score, model for end-stage liver disease score, and other indicators were gradually recovered within 3 months to 1 year after PBSC treatment, and stabilized at a more desirable level in the long-term after follow-up for up to 10 years. There was no statistically significant difference in the incidence of liver cancer between the two groups (25.22% vs.31.85%, P=0.267). The age of onset of hepatocellular carcinoma was later in PBSC than control group [(56.66±7.21) years vs. (52.69±8.42) years, P<0.05]. Conclusions: This long-term observational follow-up study of more than ten years confirms that PBSC treatment can bring long-term benefits to patients with decompensated cirrhosis, with good long-term safety, thus providing more data support on the safety and efficacy of stem cells for clinical applications.

[Analysis of clinical features and prognosis of acute severe autoimmune hepatitis].

Objective: To analyze the clinical features and prognosis of acute severe autoimmune hepatitis (AIH). Methods: A retrospective analysis of the clinical data of patients with acute severe AIH admitted to our hospital from 2008 to 2019 was divided into acute AIH (A-AIH) and chronic acute AIH (AC-AIH) according to the presence or absence of liver diseases. Patients' general condition, liver biochemistry, immunology, histological features of liver, hormonal therapies prognosis and related factors were analyzed. Results: A total of 41 cases [39 females, age (54.24 ± 10.55) years] were collected. Alanine aminotransferase (ALT) and total bilirubin (TBil) were significantly increased, and the international normalized ratio (INR) was > 1.5. Acute lobular inflammation was the feature of acute and severe AIH in the histology of liver. The serum IgG level was (28.36 ± 8.35) g / L. The positive rate of antinuclear antibody (ANA) and anti-smooth muscle antibody (ASMA) was 82.9%, and 17.1%, respectively. Over 70% of acute severe AIHs were AC-AIH. The duration of onset of AC-AIH was > 8 weeks, while most A-AIHs < 8 weeks, and the differences between the two groups were statistically significant (P = 0.001). The mortality rate within 30 days after hormonal treatment was 19.5%. There were statistically significant differences in TBil, Model for End-Stage Liver Disease (MELD) score and leukocyte count between the death and survival group. Conclusion: The mortality rate in acute severe AIH is high, and most of them have the basis of chronic liver disease. Serum IgG level, autoantibodies and acute lobular inflammation are important factors for diagnosis. The prognosis of hormonal therapy is related to the patients' condition and course of disease.

Identifying C2H4N4 structural isomers using fs-laser induced breakdown spectroscopy.

Four C2H4N4 structural isomers are investigated with fs laser-induced breakdown spectroscopy. Plasma emissions, C I, Hα, the CN violet system (B2Σ+-X2Σ+, Δν = 0 sequence) and C2 swan system (d3Πg-a3Πu, Δν = 0 sequence) are measured. The temporal evolution of the characteristic emission intensity is obtained for each emission and their lifetimes are calculated. The lifetimes of the molecular emissions are much longer than those of the atomic emissions. Characteristic emission intensities and lifetime are correlated with the molecular structures of the four isomers to a certain extent. Plasma temperature is extracted by fitting the spectrum of the CN violet system, B2Σ+-X2Σ+; Δν = 0 sequence, and is weakly correlated with the molecular structures of the four isomers. Using the characteristic emission intensities as input, principal component analysis (PCA) and artificial neural network (ANN) analysis are performed and the individual isomers can be well identified with PCA or ANN.

The influence of morphological distribution of melanin on parameter selection in laser thermotherapy for vascular skin diseases.

Port wine stains (PWSs) are congenital vascular malformations that progressively darken and thicken with age. Currently, laser therapy is the most effective way in clinical management of PWS. It is known that skin pigmentation (melanin content) affects the radiant exposure that can be safely applied to treat PWS. However, the effect of melanin distribution in the epidermis on the maximum safe radiant exposure has not been studied previously. In this study, 10 different morphological distributions of melanin were proposed according to the formation and migration characteristics of melanin, and the two-scale heat transfer model was employed to investigate the influence of melanin distribution on the threshold radiant exposure of epidermis and blood vessels. The results show that melanin distributions do have a strong effect on laser parameter selection. When uniform melanin distribution is assumed, the threshold radiant exposure to damage a typical PWS blood vessel (50 µm diameter) is 8.62 J/cm2 lower than that to injure epidermis. The optimal pulse duration is 1-5 ms for a typical PWS blood vessel of 50 µm when melanin distribution is taken into consideration. PWS blood vessels covered by non-uniformly distributed melanin are more likely to have poor response to laser treatment.

Theoretical Investigation on Hydrogen Abstraction by NO2 from Symmetric Ethers (CH3)2 xO ( x = 1-4).

Hydrogen abstractions by NO2 from symmetric ethers are investigated to determine the rate constants and explore the effect of the functional group on rate constants at different reaction sites. The involved ethers are dimethyl ether (DME), diethyl ether (DEE), dipropyl ether (DPE), and dibutyl ether (DBE). The B3LYP method with a 6-31G(2df,p) basis set is employed to optimize the ground-state geometries and for frequency and intrinsic reaction coordinate calculations. The G4 method is used to calculate the electronic energies for the small ethers (DME and DEE). Given the heavy computational cost of the G4 method, the modified G4MP2 method is applied for larger ethers (DPE and DBE) and also for DME to verify the accuracy of the G4MP2 method by benchmarking with the G4 method. The high-pressure limit rate constants are calculated within the temperature range of 500-2000 K, with the asymmetrical Eckart tunneling correction as well as one-dimensional hindered rotor treatment. The calculated rate constants agree well with the literature data, and the branch ratio analysis suggests that the cis-HONO channel basically dominates the hydrogen abstraction reactions and shows a decrease at high temperatures, followed by HNO2 and trans-HONO channels; in addition, the hydrogen abstraction at the C site adjacent to the ether bond (α reaction site) accounts for most of the reactions. Furthermore, the total rate constants of the ethers are compared to those of their half-structurally alkanes, and linear Bell-Evans-Polanyi correlations are observed.

Germ cell-specific Atg7 knockout results in primary ovarian insufficiency in female mice.

Primary ovarian insufficiency (POI) is a common cause of infertility in around 1-2% of women aged <40 years. However, the mechanisms that cause POI are still poorly understood. Here we showed that germ cell-specific knockout of an essential autophagy induction gene Atg7 led to subfertility in female mice. The subfertility of Atg7 deletion females was caused by severe ovarian follicle loss, which is very similar to human POI patients. Further investigation revealed that germ cell-specific Atg7 knockout resulted in germ cell over-loss at the neonatal transition period. In addition, our in vitro studies also demonstrated that autophagy could protect oocytes from over-loss by apoptosis in neonatal ovaries under the starvation condition. Taken together, our results uncover a new role for autophagy in the regulation of ovarian primordial follicle reservation and hint that autophagy-related genes might be potential pathogenic genes to POI of women.

Far-lateral disk herniation: treatment by automated percutaneous diskectomy.

Automated percutaneous diskectomy has certain advantages over other surgical approaches to the treatment of far-lateral disk herniation; primarily, the procedure can be performed under local anesthesia without soft-tissue disruption. We describe four patients with far-lateral herniations who were successfully treated with the procedure.

Percutaneous automated biopsy in the diagnosis of primary infectious spondylitis.

Three cases of primary infectious spondylitis, two caused by Staphylococcus aureus and one by tuberculosis, were diagnosed using the method previously described for automated percutaneous discectomy. All three patients, in whom biopsy using fine needle techniques previously was unsuccessful, had positive cultures from specimens obtained using the automated method. The method combines the advantages of local anesthesia and minimal morbidity with the obtaining of adequate material for culture and pathological examination.