In this paper, a novel in-wheel motor (IWM) topology scheme is brought forward. This scheme aims at conquering the unspung mass increase because of the motor embedded in the wheel and the motor ...magnet gap (MMG) deformation that arose by road surface roughness excitation. By mounting rubber bushings in the IWM device, the IWM mass is flexibly isolated from the unsprung mass. Synchronously, the rubber bushings can absorb the vibration energy from the road surface and abate the MMG deformation. Primarily, the quarter vehicle vibration dynamic model is set up. Then, bushing stiffness and damping are analyzed plainly. By contrastive simulations of the two types of IWM schemes with or without bushings, some useful results come out. With the rubber bushings, the body vibration acceleration, the tire dynamic load, the suspension dynamic travel, and the magnet gap deformation (MGD) can all achieve distinct improvements. In particular, MGD gets more than 90% improvement. Consequently, rubber bushings can observably improve the IWM vehicle vertical dynamics. The scheme and the analysis approach can be contributive to the development of the IWM propulsion system.
Inflammation affects regeneration of the intestinal epithelia; long noncoding RNAs (lncRNAs) regulate cell functions, such as proliferation, differentiation, and migration. We investigated the ...mechanisms by which the lncRNA H19, imprinted maternally expressed transcript (H19) regulates regeneration of intestinal epithelium using cell cultures and mouse models of inflammation.
We performed RNA-sequencing transcriptome analyses of intestinal tissues from mice with lipopolysaccharide (LPS)-induced sepsis to identify lncRNAs associated with inflammation; findings were confirmed by quantitative real-time polymerase chain reaction and in situ hybridization analyses of intestinal tissues from mice with sepsis or dextran sulfate sodium (DSS)–induced mucosal wound healing and patients with ulcerative colitis compared to healthy individuals (controls). We screened cytokines for their ability to induce expression of H19 in HT-29 cells and intestinal epithelial cells (IECs), and confirmed findings in crypt epithelial organoids derived from mouse small intestine. IECs were incubated with different signal transduction inhibitors and effects on H19 lncRNA levels were measured. We assessed intestinal epithelial proliferation or regeneration in H19ΔEx1/+ mice given LPS or DSS vs wild-type littermates (control mice). H19 was overexpressed in IECs using lentiviral vectors and cell proliferation was measured. We performed RNA antisense purification, RNA immunoprecipitation, and luciferase reporter assays to study functions of H19 in IECs.
In RNA-sequencing transcriptome analysis of lncRNA expression in intestinal tissues from mice, we found that levels of H19 lncRNA changed significantly with LPS exposure. Levels of H19 lncRNA increased in intestinal tissues of patients with ulcerative colitis, mice with LPS-induced and polymicrobial sepsis, or mice with DSS-induced colitis, compared with controls. Increased H19 lncRNA localized to epithelial cells in the intestine, regardless of Lgr5 messenger RNA expression. Exposure of IECs to interleukin 22 (IL22) increased levels of H19 lncRNA with time and dose, which required STAT3 and protein kinase A activity. IL22 induced expression of H19 in mouse intestinal epithelial organoids within 6 hours. Exposure to IL22 increased growth of intestinal epithelial organoids derived from control mice, but not H19ΔEx1/+ mice. Overexpression of H19 in HT-29 cells increased their proliferation. Intestinal mucosa healed more slowly after withdrawal of DSS from H19ΔEx1/+ mice vs control mice. Crypt epithelial cells from H19ΔEx1/+ mice proliferated more slowly than those from control mice after exposure to LPS. H19 lncRNA bound to p53 and microRNAs that inhibit cell proliferation, including microRNA 34a and let-7; H19 lncRNA binding blocked their function, leading to increased expression of genes that promote regeneration of the epithelium.
The level of lncRNA H19 is increased in inflamed intestinal tissues from mice and patients. The inflammatory cytokine IL22 induces expression of H19 in IECs, which is required for intestinal epithelial proliferation and mucosal healing. H19 lncRNA appears to inhibit p53 protein and microRNA 34a and let-7 to promote proliferation of IECs and epithelial regeneration.
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Switchable structured adhesion on rough surfaces is highly desired for a wide range of applications. Combing the advantages of gecko seta and creeper root, a switchable fibrillar adhesive composed of ...polyurethane (PU) as the backing layer and graphene/shape memory polymer (GSMP) as the pillar array is developed. The photothermal effect of graphene (under UV irradiation) changes GSMP micropillars into the viscoelastic state, allowing easy and intimate contact on surfaces with a wide range of roughness. By controlling the phase state of GSMP via UV irradiation during detachment, the GSMP micropillar array can be switched between the robust‐adhesion state (UV off) and low‐adhesion state (UV on). The state of GSMP micropillars determines the adhesion force capacity and the stress distribution at the detaching interface, and therefore the adhesion performance. The PU‐GSMP adhesive achieves large adhesion strength (278 kPa), high switching ratio (29), and fast switching (10 s) at the same time. The results suggest a design principle for bioinspired structured adhesives, especially for reversible adhesion on surfaces with a wide range of roughness.
The phase change of micropillar arrays between viscoelastic and glassy states switches the adhesion force capacity and the stress distribution at the detaching interface, and therefore the adhesion performance on surfaces with a wide range of roughness. The adhesive proposed can achieve large adhesion strength (278 kPa), high switching ratio (29), and fast switching (10 s) at the same time.
Holographic complexity bounds Liu, Hai-Shan; Lü, H.; Ma, Liang ...
The journal of high energy physics,
07/2020, Letnik:
2020, Številka:
7
Journal Article
Recenzirano
Odprti dostop
A
bstract
We study the action growth rate in the Wheeler-DeWitt (WDW) patch for a variety of
D ≥
4 black holes in Einstein gravity that are asymptotic to the anti-de Sitter spacetime, with spherical, ...toric and hyperbolic horizons, corresponding to the topological parameter
k
= 1
,
0
, −
1 respectively. We find a lower bound inequality
1
T
∂
I
⋅
WDW
∂
S
Q
,
P
th
>
C
for
k
= 0
,
1, where
C
is some order-one numerical constant. The lowest number in our examples is
C
= (
D −
3)
/
(
D −
2). We also find that the quantity
I
⋅
WDW
−
2
P
th
Δ
V
th
is greater than, equal to, or less than zero, for
k
= 1
,
0
, −
1 respectively. For black holes with two horizons, ∆
V
th
=
V
th
+
−
V
th
−
, i.e. the difference between the thermodynamical volumes of the outer and inner horizons. For black holes with only one horizon, we introduce a new concept of the volume
V
th
0
of the black hole singularity, and define
Δ
V
th
=
V
th
+
−
V
th
0
. The volume
V
th
0
vanishes for the Schwarzschild black hole, but in general it can be positive, negative or even divergent. For black holes with single horizon, we find a relation between
I
⋅
WDW
and
V
th
0
, which implies that the holographic complexity preserves the Lloyd’s bound for positive or vanishing
V
th
0
, but the bound is violated when
V
th
0
becomes negative. We also find explicit black hole examples where
V
th
0
and hence
I
⋅
WDW
are divergent.
Checkpoint-blockade immunotherapy targeting programmed cell death protein 1 (PD-1) has recently shown promising efficacy in hepatocellular carcinoma (HCC). However, the factors affecting and ...predicting the response to anti-PD-1 immunotherapy in HCC are still unclear. Herein, we report the dynamic variation characteristics and specificities of the gut microbiome during anti-PD-1 immunotherapy in HCC using metagenomic sequencing.
Fecal samples from patients responding to immunotherapy showed higher taxa richness and more gene counts than those of non-responders. For dynamic analysis during anti-PD-1 immunotherapy, the dissimilarity of beta diversity became prominent across patients as early as Week 6. In non-responders, Proteobacteria increased from Week 3, and became predominant at Week 12. Twenty responder-enriched species, including Akkermansia muciniphila and Ruminococcaceae spp., were further identified. The related functional genes and metabolic pathway analysis, such as carbohydrate metabolism and methanogenesis, verified the potential bioactivities of responder-enriched species.
Gut microbiome may have a critical impact on the responses of HCC patients treated with anti-PD-1 immunotherapy. The dynamic variation characteristics of the gut microbiome may provide early predictions of the outcomes of immunotherapy in HCC, which is critical for disease-monitoring and treatment decision-making.
Chronic low-grade inflammation is a hallmark of aging, which is now coined as inflamm-aging. Inflamm-aging contributes to many age-associated diseases such as obesity, type 2 diabetes, cardiovascular ...disease, and inflammatory bowel disease (IBD). We have shown that gut hormone ghrelin, via its receptor growth hormone secretagogue receptor (GHS-R), regulates energy metabolism and inflammation in aging. Emerging evidence suggests that gut microbiome has a critical role in intestinal immunity of the host. To determine whether microbiome is an integral driving force of GHS-R mediated immune-metabolic homeostasis in aging, we assessed the gut microbiome profiles of young and old GHS-R global knockout (KO) mice. While young GHS-R KO mice showed marginal changes in Bacteroidetes and Firmicutes, aged GHS-R KO mice exhibited reduced Bacteroidetes and increased Firmicutes, featuring a disease-susceptible microbiome profile. To further study the role of GHS-R in intestinal inflammation in aging, we induced acute colitis in young and aged GHS-R KO mice using dextran sulfate sodium (DSS). The GHS-R KO mice showed more severe disease activity scores, higher proinflammatory cytokine expression, and decreased expression of tight junction markers. These results suggest that GHS-R plays an important role in microbiome homeostasis and gut inflammation during aging; GHS-R suppression exacerbates intestinal inflammation in aging and increases vulnerability to colitis. Collectively, our finding reveals for the first time that GHS-R is an important regulator of intestinal health in aging; targeting GHS-R may present a novel therapeutic strategy for prevention/treatment of aging leaky gut and inflammatory bowel disease.
In this paper, we adopt the so-called Buonanno-Kidder-Lehner (BKL) recipe to estimate the final spin of a rotating binary black hole merger in STU supergravity. According to the BKL recipe, the final ...spin can be viewed as the sum of the individual spins plus the orbital angular momentum of the binary system which could be approximated as the angular momentum of a test particle orbiting at the innermost stable circular orbit around the final black hole. Unlike previous works, we consider the contribution of the orbital angular momentum of the binary system to the final spin by requiring the test particle to preserve the scaling symmetry in the Lagrangian of supergravity. We find some subtle differences between two cases corresponding to whether the symmetry is taken into account or not. In the equal initial spin configuration, when the initial black holes are non-spinning, the final spin of the merger is always larger than that in the case in which the symmetry is not imposed although the general behaviors are similar. The difference increases firstly and then decreases as the initial mass ratio approaches unity. Besides, as the initial spins exceed a threshold, the final spin is always smaller than that in the case where the scaling symmetry is not considered. The difference decreases constantly as the equal initial mass limit is approached. All these features exist in the merger of a binary STU black hole with different charge configurations. We also study the final spin's difference between different charge configurations and different initial spin configurations.
Biological materials achieve directional reinforcement with oriented assemblies of anisotropic building blocks. One such example is the nanocomposite structure of keratinized epithelium on the toe ...pad of tree frogs, in which hexagonal arrays of (soft) epithelial cells are crossed by densely packed and oriented (hard) keratin nanofibrils. Here, a method is established to fabricate arrays of tree-frog-inspired composite micropatterns composed of polydimethylsiloxane (PDMS) micropillars embedded with polystyrene (PS) nanopillars. Adhesive and frictional studies of these synthetic materials reveal a benefit of the hierarchical and anisotropic design for both adhesion and friction, in particular, at high matrix–fiber interfacial strengths. The presence of PS nanopillars alters the stress distribution at the contact interface of micropillars and therefore enhances the adhesion and friction of the composite micropattern. The results suggest a design principle for bioinspired structural adhesives, especially for wet environments.
An in-wheel motor (IWM) drive system highly integrates the drive motor, deceleration mechanism, and brake, among others, in the wheel, resulting in difficulty dissipating heat. The uneven temperature ...distribution of the motor is caused by its eccentricity owing to road excitation, tire bounce, and installation errors. This non-uniformity generates thermal stress that endangers motor operation and also causes the motor’s local temperature to increase substantially, thereby affecting its performance. To solve this problem, this study takes a 15 kW IWM as research object to quantitatively analyze the temperature distribution of rated and peak conditions of the motor under different eccentricities. The influence law of eccentricity on the thermal characteristics of IWM is obtained. Results show that the eccentricity of motor has substantial influence on the temperature distribution of stator and rotor.
Phloem-feeding insects cause massive losses in agriculture and horticulture. Host plant resistance to phloem-feeding insects is often mediated by changes in phloem composition, which deter insect ...settling and feeding and decrease viability. Here, we report that rice plant resistance to the phloem-feeding brown planthopper (BPH) is associated with fortification of the sclerenchyma tissue, which is located just beneath the epidermis and a cell layer or two away from the vascular bundle in the rice leaf sheath. We found that BPHs prefer to feed on the smooth and soft region on the surface of rice leaf sheaths called the long-cell block. We identified Bph30 as a rice BPH resistance gene that prevents BPH stylets from reaching the phloem due to the fortified sclerenchyma. Bph30 is strongly expressed in sclerenchyma cells and enhances cellulose and hemicellulose synthesis, making the cell walls stiffer and sclerenchyma thicker. The structurally fortified sclerenchyma is a formidable barrier preventing BPH stylets from penetrating the leaf sheath tissues and arriving at the phloem to feed. Bph30 belongs to a novel gene family, encoding a protein with two leucine-rich domains. Another member of the family, Bph40, also conferred resistance to BPH. Collectively, the fortified sclerenchyma-mediated resistance mechanism revealed in this study expands our understanding of plant-insect interactions and opens a new path for controlling planthoppers in rice.
In this study, Shi et al. discover that brown planthopper (BPH) inserts its stylets into the smooth area on the rice leaf sheath surface and then BPH stylets pass through the sclerenchyma on the path to sucking the phloem sap. The authors further identify a Bph30-mediated resistance mechanism that makes the sclerenchyma a formidable barrier preventing BPH stylets from penetrating and feeding.
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