Interaction dynamics of optical dark bound solitons for a defocusing Lakshmanan-Porsezian-Daniel equation.

We investigate the propagation and interaction dynamics of the optical dark bound solitons for the defocusing Lakshmanan-Porsezian-Daniel equation, which is a physically relevant generalization of the nonlinear Schrödinger equation involving the higher-order effects. Explicit N-dark soliton solutions in the compact determinant form are constructed via the binary Darboux transformation method. Bound states of the dark solitons are discussed when the incoherent solitons have the same velocity. We find an interesting phenomenon that dark soliton molecules and double-valley dark solitons (DVDSs) can be obtained by controlling the interval of the bound state dark solitons, and abundant interaction modalities between them can be formed. Moreover, dark soliton molecules always undergo elastic interactions with other solitons, while interactions for the DVDSs are usually inelastic, and special parameter conditions for elastic interaction of DVDSs through asymptotic analysis are obtained. Numerical simulations are employed to verify the stability of the bound state dark solitons. Analytical results obtained in this paper are expected to be useful for the experimental realization of bound-state dark solitons in optical fibers with higher-order effects and a further understanding of their optical transmission properties..

Recurrent de novo single point variant on the gene encoding Na+/K+ pump results in epilepsy.

The etiology of epilepsy remains undefined in two-thirds of patients. Here, we identified a de novo variant of ATP1A2 (c.2426 T > G, p.Leu809Arg), which encodes the α2 subunit of Na+/K+-ATPase, from a family with idiopathic epilepsy. This variant caused epilepsy with hemiplegic migraine in the study patients. We generated the point variant mouse model Atp1a2L809R, which recapitulated the epilepsy observed in the study patients. In Atp1a2L809R/WT mice, convulsions were observed and cognitive and memory function was impaired. This variant affected the potassium binding function of the protein, disabling its ion transport ability, thereby increasing the frequency of nerve impulses. Valproate (VPA) and Carbamazepine (CBZ) have limited therapeutic efficacy in ameliorating the epileptic syndromes of Atp1a2L809R/WT mice. Our work revealed that ATP1A2L809R variants cause a predisposition to epilepsy. Moreover, we provide a point variant mouse model for epilepsy research and drug screening.

TNF-α - mediated peripheral and central inflammation are associated with increased incidence of PND in acute postoperative pain.

BACKGROUND: Acute postoperative pain plays an important role in the perioperative neurocognitive disorders (PND). The pathogenesis of PND is still unknown, but it is generally believed that peripheral and central nervous system inflammation play an important role, and acute postoperative pain is also thought to aggravate postoperative inflammatory response. The aim of the present study is to explore the effect of acute postoperative pain on peripheral and central nervous system inflammation and related cognitive impairment behaviour in elderly rats after surgery. METHODS: Rats were assigned into four groups: control, surgery for internal fixation for tibial fracture, surgery with analgesia using intraperitoneal morphine, and morphine without surgery. Pain was assessed by the Subjective Pain Scale. The spatial memory of rats was assessed by the Morris water maze (delayed matching task) from the second day to the seventh day after surgery (POD2-POD7). In part of the rats, the pro-inflammatory cytokines TNF-α in plasma, the medial prefrontal cortex (mPFC), and the hippocampus were determined by ELISA on the POD2. The activation of microglia and the expression of c-Fos in the hippocampal CA1 regions and mPFC were detected by the immunohistochemical method on the POD2. RESULTS: Acute postoperative pain and spatial memory impairment occurred after operation, and postoperative analgesia could significantly improve the both parameters. Additionally, on the POD2, the levels of TNF-α in plasma, hippocampus and mPFC were significantly increased, while the activation of microglia cells and the expression c-Fos in the hippocampal CA1 regions and mPFC were significantly increased. And postoperative analgesia with morphine significantly inhibited the above reactions. CONCLUSION: Our data suggest that acute postoperative pain increases the incidence of perioperative neurocognitive disorders. Peripheral and central nervous system inflammation may be involved in this cognitive impairment. And reducing the intensity of acute postoperative pain may be one of the main preventive strategies for PND.

The effect of transversus abdominis plane block on the chronic pain after colorectal surgery: a retrospective cohort study.

BACKGROUND: Chronic postsurgical pain (CPSP) is common and would reduce the quality of life of patients. Transversus abdominal plane (TAP) block has been widely used in lower abdominal surgery and many researches demonstrated that it could improve acute postsurgical pain. We aim to determine whether TAP block could improve chronic postoperative pain at 3 months and 6 months after colorectal surgery. METHODS: A total of 307 patients received selective colorectal surgery under general anesthesia between January, 2015 and January, 2019 in a single university hospital were included: 128 patients received TAP block combined with patient-controlled intravenous analgesia (PCIA) for postsurgical analgesia (group TP) and 179 only administrated with PCIA (group P). Main outcome was the NRS score of pain at 3 months after colorectal surgery. The data was analyzed by two-way repeated measures anova and the chi-square test. RESULTS: The NRS score at rest and during movement was decreased significantly at 24 h after surgery (rest NRS 1.07 ± 1.34 vs 1.65 ± 1.67, movement NRS 3.00 ± 1.45 vs 3.65 ± 1.89; all P = 0.003) in group TP than those of group P. There was no significant difference of NRS score at 48 h after surgery (P > 0.05). At 3 months after surgery, the NRS score during movement was also lower in group TP than that in group P (0.59 ± 1.23 vs 0.92 ± 1.65, P = 0.045). There was no significant difference of NRS score at 6 months after surgery (P > 0.05). The prevalence of CPSP was 19.5% (25/128) in group TP and 20.7% (37/179) in group P at 3 months after surgery. 13.2% (17/128) of patients suffered from CPSP in group TP and 13.9% (25/179) in group P at 6 months after surgery. Both at 3 months and 6 months after surgery, there was no statistical difference of the prevalence of CPSP between the two groups (all P > 0.05) . CONCLUSIONS: TAP block reduced NRS during movement at 3 months after surgery but did not reduce the incidence of CPSP at 3 months and 6 months after selective colorectal surgery.

Preliminary study of urine metabolism in type two diabetic patients based on GC-MS.

OBJECTIVE: Comparative study of type 2 diabetes and healthy controls by metabolomics methods to explore the pathogenesis of Type II diabetes. METHODS: Gas chromatography - mass spectrometry (GC-MS) with a variety of multivariate statistical analysis methods to the healthy control group 58 cases, 68 cases of Type II diabetes group were analyzed. Chromatographic conditions: DB-5MS column; the carrier gas He; flow rate of 1 mL·min(-1), the injection volume 1 uL; split ratio is 100: 1. MS conditions: electron impact (EI) ion source, an auxiliary temperature of 280°C, the ion source 230°C, quadrupole 150°C; mass scan range 30~600 mAu. RESULTS: Established analytical method based on urine metabolomics GC-MS of Type II diabetes, determine the urine succinic acid, L-leucine, L-isoleucine, tyrosine, slanine, acetoace acid, mannose, L-isoleucine, L-threonine, Phenylalanine, fructose, D-glucose, palmi acid, oleic acid and arachidonic acid were significantly were significantly changed. CONCLUSION: Based on metabolomics of GC-MS detection and analysis metabolites can be found differences between type 2 diabetes and healthy control group, PCA diagram can effectively distinguish Type II diabetes and healthy control group, with load diagrams and PLS-DA VIP value metabolite screening, the resulting differences in metabolic pathways involved metabolites, including amino acid metabolism, lipid metabolism, glucose metabolism and energy metabolism.

Tramadol combined with fentanyl in awake endotracheal intubation.

OBJECTIVE: To explore the feasibility and dosage of tramadol combined with fentanyl in awake endotracheal intubation. METHODS: Using Dixon's up-and-down sequential design, the study enrolled patients from each of the 20-49, 50-60 and 70-and-above age groups scheduled for elective surgery under general anesthesia. The feasibility and dosage of tramadol combined with fentanyl in awake endotracheal intubation, guided by fiberoptic bronchoscopy, were verified. RESULTS: After intravenous injection with fentanyl 2.2 µg/kg and tramadol 2.0 mg/kg in the 20-49 age group, fentanyl 1.6 µg/kg and tramadol 1.9 mg/kg in the 50-69 age group and fentanyl 1 µg/kg and tramadol 1.8 mg/kg in those at the age of 70 or above, the patients achieved conscious sedation without obvious respiratory depression. Meanwhile, under these dosages, the patients could easily tolerate the thyrocricocentesis airway surface anesthesia and fiberoptic bronchoscope guided tracheal intubation. Postoperative follow-up showed that most patients had memory of the intubation process but without significant discomfort. No awake endotracheal intubation-related side effect was noted. CONCLUSIONS: Fiberoptic bronchoscope guided nasotracheal intubation can be successfully completed with background administration of fentanyl and tramadol. However, the specific dosages need to be tailored in different age of patients.

Molecular mechanism of interaction and electron transfer between dihydric phenols and L-cysteine.

The mechanism and electron transfer for pollutant dihydric phenol and biomolecule L-Cysteine (L-Cys) interaction in aqueous solution were studied by means of electrochemistry and UV-VIS spectrophotometry. Two forms of L-Cys, fixed on Au-electrode and free dissolved in the solution, were examined. The results showed that L-Cys of an ordered monolayer fixed on an Au electrode facilitated electron transfer and electrocatalytic redox of three isomers of dihydric phenol. However, free L-Cys does not show such facility. Furthermore, neither cleavage of the original chemical bond nor formation of a new chemical bond was observed in the molecules investigated, suggesting that L-Cys molecules may associate tightly with dihydric phenol molecules to form L-Cys . C(6)H(6)O(2)or (L-Cys) (2) . C(6)H(6)O(2) complex molecule via hydrogen-bonding. Different coordination numbers influence the electrochemical activity and behavior of associated complexes; thus, the function of biomolecules could be affected.

BCL-xL overexpression effectively protects against tetrafluoroethylcysteine-induced intramitochondrial damage and cell death.

S-(1,1,2,2-Tetrafluoroethyl)-L-cysteine (TFEC), a major metabolite of the industrial gas tetrafluoroethylene, has been shown to mediate nephrotoxicity by necrosis. TFEC-induced cell death is associated with an early covalent modification of specific intramitochondrial proteins; including aconitase, alpha-ketoglutarate dehydrogenase (KGDH) subunits, HSP60 and HSP70. Previous studies have indicated that the TAMH line accurately models TFEC-induced in vivo cell death with dose- and time-dependent inhibitions of both KGDH and aconitase activities. Here, we show that the molecular pathway leading to TFEC-mediated cell death is associated with an early cytosolic to mitochondrial translocation of BAX, a pro-apoptotic member of the BCL-2 family. Immunoblot analyses indicated movement of BAX (21 kDa) to the mitochondrial fraction after exposure to a cytotoxic concentration of TFEC (250 microM). Subsequent cytochrome c release from mitochondria was also demonstrated, but only a modest increase in caspase activities was observed, suggesting a degeneration of early apoptotic signals into secondary necrosis. Significantly, TAMH cells overexpressing BCL-xL preserved cell viability even to supratoxicological concentrations of TFEC (< or =600 microM), and this cytoprotection was associated with decreased HSP70i upregulation, indicating suppression of TFEC-induced proteotoxicity. Hence, TFEC-induced necrotic cell death in the TAMH cell line is mediated by BAX and antagonized by the anti-apoptotic BCL-2 family member, BCL-xL.