We study the
P
cs
(
4459
)
0
recently observed by LHCb using the method of QCD sum rules. Our results support its interpretation as the
D
¯
∗
Ξ
c
hadronic molecular state of either
J
P
=
1
/
2
-
or
3
.../
2
-
. Within the hadronic molecular picture, the three LHCb experiments observing
P
c
and
P
cs
states (Aaij et al., Phys Rev Lett 115:072001, 2015; Aaij et al., Phys Rev Lett 122:222001, 2019; Aaij et al.,
arXiv:2012.10380
hep-ex, 2012) can be well understood as a whole. This strongly supports the existence of hadronic molecules, whose studies can significantly improve our understanding on the construction of the subatomic world. To verify this picture, we propose to further investigate the
P
cs
(
4459
)
0
to examine whether it can be separated into two states, and to search for the
D
¯
Ξ
c
molecular state of
J
P
=
1
/
2
-
.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Highly efficient hydrogen evolution reaction (HER) electrocatalyst will determine the mass distributions of hydrogen‐powered clean technologies, while still faces grand challenges. In this work, a ...synergistic ligand modulation plus Co doping strategy is applied to 1T−MoS2 catalyst via CoMo‐metal‐organic frameworks precursors, boosting the HER catalytic activity and durability of 1T−MoS2. Confirmed by Cs corrected transmission electron microscope and X‐ray absorption spectroscopy, the polydentate 1,2‐bis(4‐pyridyl)ethane ligand can stably link with two‐dimensional 1T−MoS2 layers through cobalt sites to expand interlayer spacing of MoS2 (Co−1T−MoS2‐bpe), which promotes active site exposure, accelerates water dissociation, and optimizes the adsorption and desorption of H in alkaline HER processes. Theoretical calculations indicate the promotions in the electronic structure of 1T−MoS2 originate in the formation of three‐dimensional metal‐organic constructs by linking π‐conjugated ligand, which weakens the hybridization between Mo‐3d and S‐2p orbitals, and in turn makes S‐2p orbital more suitable for hybridization with H‐1s orbital. Therefore, Co−1T−MoS2‐bpe exhibits excellent stability and exceedingly low overpotential for alkaline HER (118 mV at 10 mA cm−2). In addition, integrated into an anion‐exchange membrane water electrolyzer, Co−1T−MoS2‐bpe is much superior to the Pt/C catalyst at the large current densities. This study provides a feasible ligand modulation strategy for designs of two‐dimensional catalysts.
A synergistic ligand modulation plus cobalt doping strategy is applied to modulate the orbital hybridization of 1T‐MoS2 catalyst via CoMo‐MOF precursors. The polydentate 1,2‐bis(4‐pyridyl)ethane (bpe) ligand can stably link with 1T‐MoS2 layers to achieve expanded interlayer spacing, which promotes the joint participation of highly efficient active sites in the basal plane and the interlayer in alkaline HER processes.
Single atom catalysts (SACs) with the maximized metal atom efficiency have sparked great attention. However, it is challenging to obtain SACs with high metal loading, high catalytic activity, and ...good stability. Herein, we demonstrate a new strategy to develop a highly active and stable Ag single atom in carbon nitride (Ag‐N2C2/CN) catalyst with a unique coordination. The Ag atomic dispersion and Ag‐N2C2 configuration have been identified by aberration‐correction high‐angle‐annular‐dark‐field scanning transmission electron microscopy (AC‐HAADF‐STEM) and extended X‐ray absorption. Experiments and DFT calculations further verify that Ag‐N2C2 can reduce the H2 evolution barrier, expand the light absorption range, and improve the charge transfer of CN. As a result, the Ag‐N2C2/CN catalyst exhibits much better H2 evolution activity than the N‐coordinated Ag single atom in CN (Ag‐N4/CN), and is even superior to the Pt nanoparticle‐loaded CN (PtNP/CN). This work provides a new idea for the design and synthesis of SACs with novel configurations and excellent catalytic activity and durability.
A new Ag single atom in carbon nitride (Ag‐N2C2/CN) photocatalyst with Ag‐N2C2 configuration is developed. It affords fast charge transfer, high Ag loading, and good stability. Noteworthily, the Ag‐N2C2/CN exhibits much better hydrogen evolution activity than Ag‐N4/CN, and even superior to the platinum‐loaded CN.
Photothermal therapy (PTT) has attracted tremendous attention due to its noninvasiveness and localized treatment advantages. However, heat shock proteins (HSPs) associated self‐preservation ...mechanisms bestow cancer cells thermoresistance to protect them from the damage of PTT. To minimize the thermoresistance of cancer cells and improve the efficacy of PTT, an integrated on‐demand nanoplatform composed of a photothermal conversion core (gold nanorod, GNR), a cargo of a HSPs inhibitor (triptolide, TPL), a mesoporous silica based nanoreservoir, and a photothermal and redox di‐responsive polymer shell is developed. The nanoplatform can be enriched in the tumor site, and internalized into cancer cells, releasing the encapsulated TPL under the trigger of intracellular elevated glutathione and near‐infrared laser irradiation. Ultimately, the liberated TPL could diminish thermoresistance of cancer cells by antagonizing the PTT induced heat shock response via multiple mechanisms to maximize the PTT effect for cancer treatment.
A triptolide nanoreservoir, which can be in situ activated by near‐infrared light (NIR) laser irradiation and intracellular high redox potential, is developed to overcome the thermoresistance of cancer cells. Thanks to the inhibited photothermal therapy (PTT) induced heat shock response, the photothermal therapy efficacy of the gold nanorod/mesoporous nanocomplex is greatly improved.
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Despite its prevalence in the management of peripheral tumors, compared to surgery and radiation therapy, chemotherapy is still a suboptimal intervention in fighting against brain ...cancer and cancer brain metastases. This discrepancy is mainly derived from the complicatedly physiological characteristic of intracranial tumors, including the presence of blood–brain barrier (BBB) and limited enhanced permeability and retention (EPR) effect attributed to blood–brain tumor barrier (BBTB), which largely lead to insufficient therapeutics penetrating to tumor lesions to produce pharmacological effects. Therefore, dependable methodologies that can boost the efficacy of chemotherapy for brain tumors are urgently needed. Recently, nanomedicines have shown great therapeutic potential in brain tumors by employing various transcellular strategies, paracellular strategies, and their hybrids, such as adsorptive-mediated transcytosis, receptor-mediated transcytosis, BBB disruption technology, and so on. It is compulsory to comprehensively summarize these practices to shed light on future directions in developing therapeutic regimens for brain tumors. In this review, the biological and pathological characteristics of brain tumors, including BBB and BBTB, are illustrated. After that, the emerging delivery strategies for brain tumor management are summarized into different classifications and supported with detailed examples. Finally, the potential challenges and prospects for developing and clinical application of brain tumor-oriented nanomedicine are discussed.
In this work, we design and test a parameter optimization method by Python script to meet the urgent demand for lightweight honeycomb metamaterial. The method mainly focuses on the selection of ...parameters according to the mass and Poisson’s ratio of the honeycomb metamaterial. The bidirectional re-entrant honeycomb is proposed as an objective to be optimized and the formula of Poisson's ratio is deduced theoretically to establish the internal relation. Besides, the accuracy of the Python script results is verified by static compression experimental results and theoretical results. Combined the Python script programming model with the genetic algorithm optimization method, the optimal honeycomb metamaterial solutions are obtained. Results show that the parameter optimization method using multi-island genetic algorithm (GA) can avoid a local solution’s appearance, and both the shell model and the solid model can obtain the ideal optimal solution. Furthermore, the 3D honeycomb has an admirable auxetic effect according to the optimized parameters, which provides a piece of strong evidence for the continuous application of optimization algorithms to improve the mechanical properties of honeycomb metamaterial.
Background and Aim
Irritable bowel syndrome (IBS) is a highly prevalent chronic functional gastrointestinal disorder. Recent studies have showed increasing important role of gut microbiota in the ...pathophysiological changes of IBS. Our study aims to elaborate the association between intestinal flora with the genesis and the development of IBS.
Methods
Illumina high‐throughput sequencing technology was applied to investigate microbial communities of IBS patients and healthy donors. Stool specimens from the IBS‐D patients were equally premixed and implanted into germ free C57B/6 mice to construct IBS animal model, and the normal group was also transplanted with normal premixed feces. The post‐transplant defecation and intra‐epithelial lymphocyte counts were evaluated. Microbial communities were also checked by the illumina high‐throughput sequencing technology.
Results
Fifteen genuses significantly different were found expressed in the gut flora of IBS patients, and six genuses showed significantly different abundances between the stool specimens of mice of IBS group and normal group. Among these differences, Parasutterella expression was remarkably different in both screening and validation experiments and also related to chronic intestinal inflammation; therefore, Parasutterella expression is considered in association with the development and progression of IBS.
Conclusion
Parasutterella may be related with the genesis and development of IBS and also associated with chronic intestinal inflammation in IBS patients.
The spectrum of hadrons is the manifestation of color confinement of quantum chromodynamics. Hadronic resonances correspond to poles of the S-matrix. Since 2003, lots of new hadron resonant ...structures were discovered in the mass regions from light mesons to hadrons containing a pair of a heavy quark and an antiquark. Many of them are candidates of exotic hadrons, and they are usually observed as peaks in invariant mass distributions. However, the S-matrix also has kinematical singularities due to the on-shellness of intermediate particles for a process, such as two-body thresholds and triangle singularities (TSs), and they can produce peaks as well. On the one hand, such singularities may be misidentified as resonances; on the other hand, they can be used as tools for precision measurements. In this paper, we review the threshold cusps and various triangle singularities in hadronic reactions, paying attention to their manifestations in phenomena related to exotic hadron candidates.
The biomimetic enzyme activity of cerium oxide nanoparticles (CeNPs) prefers ultrasmall particle size and bare surface. Unfortunately, those two features are not favorable for its in vivo application ...due to easy aggregation and fast renal filtration. To take advantage of the activity of CeNP for cancer therapy, a homologous targeted cerium oxide nanoparticle system, targeted CeNP (T‐CeNP), with the integration of a biodegradable dendritic mesoporous silica nanoparticle, superoxide dismutase and catalase mimicking CeNPs, and the camouflage coating of cancer cell membrane has been developed. Attributed to the homologous targeting effect of cancer cell membrane, nanoparticles with camouflage coating are retained in the tumor in an orthotopic breast cancer metastatic model. Subsequently, T‐CeNP effectively hinders cancer‐associated fibroblast transdifferentiation and reprograms it back to a normal fibroblast. Consequently, T‐CeNP coupled with doxorubicin reduces the size of primary tumors and prevents the post‐surgery lung metastasis and liver metastasis of breast cancer.
A homologous targeted cerium oxide nanoparticle system (T‐CeNP) is developed for remodeling the tumor microenvironment by inhibiting cancer‐associated fibroblast transdifferentiation and reprogramming them back to normal fibroblasts. T‐CeNP coupled with doxorubicin reduces the size of the primary tumor and prevents post‐surgery lung metastasis and liver metastasis of cancer in an orthotopic breast cancer model.
Recently LHCb declared a new structure
X
(6900) in the final state di-
J
/
ψ
which is popularly regarded as a
cc
-
c
¯
c
¯
tetraquark state. Within the Bethe–Salpeter (B–S) framework we study the ...possible
cc
-
c
¯
c
¯
bound states and the interaction between diquark (
cc
) and antidiquark (
c
¯
c
¯
). In this work
cc
(
c
¯
c
¯
) is treated as a color anti-triplet (triplet) axial-vector so the quantum numbers of
cc
-
c
¯
c
¯
bound state are
0
+
,
1
+
and
2
+
. Learning from the interaction in meson case and using the effective coupling we suggest the interaction kernel for the diquark and antidiquark system. Then we deduce the B–S equations for different quantum numbers. Solving these equations numerically we find the spectra of some excited states can be close to the mass of
X
(6900) when we assign appropriate values for parameter
κ
introduced in the interaction (kernel). We also briefly calculate the spectra of
bb
-
b
¯
b
¯
bound states. Future measurement of
bb
-
b
¯
b
¯
state will help us to determine the exact form of effective interaction.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK