A note on knot fertility. II Ito, T.
Acta mathematica Hungarica,
04/2023, Letnik:
169, Številka:
2
Journal Article
Recenzirano
Odprti dostop
A knot
K
is called (
m, n
)-fertile if for every prime knot
K
′
whose crossing number is less than or equal to
m
, there exists an
n
-crossing diagram of
K
such that one can get
K
′
from the diagram ...by changing its over-under information. We give an obstruction for knot to be (
m, n
)-fertile. As application, we prove the finiteness of
(
c
(
K
)
+
f
,
c
(
K
)
+
p
)
-fertile knots for all
f
,
p
, where
c(K)
denotes the minimum crossing number of
K
. We also discuss the number of Seifert circles and the writhe of minimum crossing diagrams.
•Route planning requires the relationships between next movements and positions.•Place cells in the hippocampus represent an animal’s next position or trajectory.•Prospective coding in place cells ...requires prefrontal-hippocampal interactions.
Animals have the ability to navigate to a desired location by making use of information about environmental landmarks and their own movements. While decades of neuroscience research have identified neurons in the hippocampus and parahippocampal structures that represent an animal’s position in space, it is still largely unclear how an animal can choose the next movement direction to reach a desired goal. As the goal destination is typically located somewhere outside of the range of sensory perception, the animal is required to rely on the internal metric of space to estimate the direction and distance of the destination to plan a next action. Therefore, the hippocampal spatial map should interact with action-planning systems in other cortical regions. In accordance with this idea, several recent studies have indicated the importance of functional interactions between the hippocampus and the prefrontal cortex for goal-directed navigation. In this paper, I will review these studies and discuss how an animal can estimate its future positions correspond to a next movement. Investigation of the navigation problem may further provide general insights into internal models of the brain for action planning.
Thrombomodulin (TM) is an endothelial anticoagulant cofactor that promotes thrombin‐mediated activation of protein C. Recently, we conducted a multicentre, double‐blind, randomized trial to evaluate ...the efficacy and safety of recombinant human soluble thrombomodulin (rhsTM, also known as ART‐123) for the treatment of disseminated intravascular coagulation (DIC), and found that rhsTM therapy is more effective and safer than low‐dose heparin therapy. Thus, in 2008, rhsTM (Recomodulin) was approved for the treatment of DIC in Japan. Here we re‐evaluate the therapeutic basis of this drug from the view of its anticoagulant, anti‐inflammatory, and cytoprotective properties. Structurally, the extracellular portion of TM is composed of three domains: an N‐terminal lectin‐like domain (TM‐D1), followed by an epidermal growth factor (EGF)‐like domain (TM‐D2), and an O‐glycosylation–rich domain (TM‐D3). TM‐D2 and TM‐D3 are important for the protein’s anticoagulant cofactor activities, i.e. inhibition of thrombin and activation of protein C. TM‐D1 plays an important role in attenuation of inflammatory responses, through inhibition of leukocyte adhesion to endothelial cells, inhibition of complement pathways, neutralization of lipopolysaccharide (LPS), and sequestration and degradation of pro‐inflammatory high‐mobility group box 1 protein (HMGB1). Thus, TM on the surface of endothelial cells prevents dissemination of pro‐coagulant and pro‐inflammatory molecules, and by doing so, allows these molecules to act locally at the site of injury. In patients with sepsis and DIC, TM expression is down‐regulated, which may result in dissemination of pro‐coagulant and pro‐inflammatory molecules throughout the systemic circulation. Replacement with rhsTM may offer therapeutic value in such conditions.
Skeletal muscle depletion, referred to as sarcopenia, predicts morbidity and mortality in patients undergoing digestive surgery. However, the impact on liver transplantation is unclear. The present ...study investigated the impact of sarcopenia on patients undergoing living donor liver transplantation (LDLT). Sarcopenia was assessed by a body composition analyzer in 124 adult patients undergoing LDLT between February 2008 and April 2012. The correlation of sarcopenia with other patient factors and the impact of sarcopenia on survival after LDLT were analyzed. The median ratio of preoperative skeletal muscle mass was 92% (range, 67–130%) of the standard mass. Preoperative skeletal muscle mass was significantly correlated with the branched‐chain amino acids to tyrosine ratio (r = −0.254, p = 0.005) and body cell mass (r = 0.636, p < 0.001). The overall survival rate in patients with low skeletal muscle mass was significantly lower than in patients with normal/high skeletal muscle mass (p < 0.001). Perioperative nutritional therapy significantly increased overall survival in patients with low skeletal muscle mass (p = 0.009). Multivariate analysis showed that low skeletal muscle mass was an independent risk factor for death after transplantation. In conclusion, sarcopenia was closely involved with posttransplant mortality in patients undergoing LDLT. Perioperative nutritional therapy significantly improved overall survival in patients with sarcopenia.
Sarcopenia is closely involved with posttransplant mortality in patients undergoing living donor liver transplantation and perioperative nutritional therapy significantly improves overall survival, even in patients with sarcopenia.
To establish an appropriate steroid treatment regimen for autoimmune pancreatitis (AIP).
A retrospective survey of AIP treatment was conducted in 17 centres in Japan. The main outcome measures were ...rate of remission and relapse.
Of 563 patients with AIP, 459 (82%) received steroid treatment. The remission rate of steroid-treated AIP was 98%, which was significantly higher than that of patients without steroid treatment (74%, 77/104; p<0.001). Steroid treatment was given for obstructive jaundice (60%), abdominal pain (11%), associated extrapancreatic lesions except the biliary duct (11%), and diffuse enlargement of the pancreas (10%). There was no relationship between the period necessary to achieve remission and the initial dose (30 mg/day vs 40 mg/day) of prednisolone. Maintenance steroid treatment was given in 377 (82%) of 459 steroid-treated patients, and steroid treatment was stopped in 104 patients. The relapse rate of patients with AIP on maintenance treatment was 23% (63/273), which was significantly lower than that of patients who stopped maintenance treatment (34%, 35/104; p = 0.048). From the start of steroid treatment, 56% (55/99) relapsed within 1 year and 92% (91/99) relapsed within 3 years. Of the 89 relapsed patients, 83 (93%) received steroid re-treatment, and steroid re-treatment was effective in 97% of them.
The major indication for steroid treatment in AIP is the presence of symptoms. An initial prednisolone dose of 0.6 mg/kg/day, is recommend, which is then reduced to a maintenance dose over a period of 3-6 months. Maintenance treatment with low-dose steroid reduces but dose not eliminate relapses.
Spatial navigation requires information about the relationship between current and future positions. The activity of hippocampal neurons appears to reflect such a relationship, representing not only ...instantaneous position but also the path towards a goal location. However, how the hippocampus obtains information about goal direction is poorly understood. Here we report a prefrontal-thalamic neural circuit that is required for hippocampal representation of routes or trajectories through the environment. Trajectory-dependent firing was observed in medial prefrontal cortex, the nucleus reuniens of the thalamus, and the CA1 region of the hippocampus in rats. Lesioning or optogenetic silencing of the nucleus reuniens substantially reduced trajectory-dependent CA1 firing. Trajectory-dependent activity was almost absent in CA3, which does not receive nucleus reuniens input. The data suggest that projections from medial prefrontal cortex, via the nucleus reuniens, are crucial for representation of the future path during goal-directed behaviour and point to the thalamus as a key node in networks for long-range communication between cortical regions involved in navigation.
Our bodies turn over billions of cells daily via apoptosis and are in turn cleared by phagocytes via the process of “efferocytosis.” Defects in efferocytosis are now linked to various inflammatory ...diseases. Here, we designed a strategy to boost efferocytosis, denoted “chimeric receptor for efferocytosis” (CHEF). We fused a specific signaling domain within the cytoplasmic adapter protein ELMO1 to the extracellular phosphatidylserine recognition domains of the efferocytic receptors BAI1 or TIM4, generating BELMO and TELMO, respectively. CHEF-expressing phagocytes display a striking increase in efferocytosis. In mouse models of inflammation, BELMO expression attenuates colitis, hepatotoxicity, and nephrotoxicity. In mechanistic studies, BELMO increases ER-resident enzymes and chaperones to overcome protein-folding-associated toxicity, which was further validated in a model of ER-stress-induced renal ischemia-reperfusion injury. Finally, TELMO introduction after onset of kidney injury significantly reduced fibrosis. Collectively, these data advance a concept of chimeric efferocytic receptors to boost efferocytosis and dampen inflammation.
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Design of chimeric receptors for efferocytosis (CHEF) to enhance efferocytosisBoosting efferocytosis via CHEF attenuates multiple inflammatory insults in vivoProtein folding and misfolded protein degradation are rate-limiting steps in efferocytosisCHEF expression can improve outcomes in ongoing disease
Chimeric receptors comprising an extracellular phosphatidylserine recognition domain and the signalling domain of a cytoplasmic adaptor protein boost clearance of apoptotic cells in damaged tissue and improve the disease outcome.
A high-efficiency CMOS rectifier circuit for UHF RFIDs was developed. The rectifier has a cross-coupled bridge configuration and is driven by a differential RF input. A differential-drive active gate ...bias mechanism simultaneously enables both low ON-resistance and small reverse leakage of diode-connected MOS transistors, resulting in large power conversion efficiency (PCE), especially under small RF input power conditions. A test circuit of the proposed differential-drive rectifier was fabricated with 0.18 mu m CMOS technology, and the measured performance was compared with those of other types of rectifiers. Dependence of the PCE on the input RF signal frequency, output loading conditions and transistor sizing was also evaluated. At the single-stage configuration, 67.5% of PCE was achieved under conditions of 953 MHz, - 12.5 dBm RF input and 10 KOmega output load. This is twice as large as that of the state-of-the-art rectifier circuit. The peak PCE increases with a decrease in operation frequency and with an increase in output load resistance. In addition, experimental results show the existence of an optimum transistor size in accordance with the output loading conditions. The multi-stage configuration for larger output DC voltage is also presented.
Frustrated magnetic materials, in which local conditions for energy minimization are incompatible because of the lattice structure, can remain disordered to the lowest temperatures. Such is the case ...for Ba₃CuSb₂O₉, which is magnetically anisotropic at the atomic scale but curiously isotropie on mesoscopic length and time scales. We find that the frustration of Wannier's Ising model on the triangular lattice is imprinted in a nanostructured honeycomb lattice of Cu⁺ ions that resists a coherent static Jahn-Teller distortion. The resulting two-dimensional random-bond spin-1/2 system on the honeycomb lattice has a broad spectrum of spin-dimer-like excitations and low-energy spin degrees of freedom that retain overall hexagonal symmetry.
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