A
bstract
We revisit the status of the new-physics interpretations of the anomalies in semileptonic
B
decays in light of the new data reported by Belle on the lepton-universality ratios
R
D
(*)
using ...the semileptonic tag and on the longitudinal polarization of the
D
*
in
B → D
*
τν
,
F
L
D
∗
. The preferred solutions involve new left-handed currents or tensor contributions. Interpretations with pure right-handed currents are disfavored by the LHC data, while pure scalar models are disfavored by the upper limits derived either from the LHC or from the
B
c
lifetime. The observable
F
L
D
∗
also gives an important constraint leading to the exclusion of large regions of parameter space. Finally, we investigate the sensitivity of different observables to the various scenarios and conclude that a measurement of the tau polarization in the decay mode
B → Dτν
would effectively discriminate among them.
In the huge number of online university education resources, it is difficult for learners to quickly locate the resources they need, which leads to “information trek.” Traditional information ...recommendation methods tend to ignore the characteristics of learners, who are the main subjects of education. In order to improve the recommendation accuracy, a recommendation algorithm based on improved collaborative filtering model is proposed in this paper. Firstly, according to the student behavior data, consider the behavior order to create the behavior graph and behavior route. Then, the path of text type is vectorized by the Keras Tokenizer method. Finally, the similarity between multidimensional behavior path vectors is calculated, and path collaborative filtering recommendations are performed for each dimension separately. The MOOC data of a university in China are introduced to experimentally compare the algorithm of the article as well as the control group algorithm. The results show that the proposed algorithm takes better values in evaluation indexes, thus verifying that this algorithm can improve the effectiveness of innovation and entrepreneurship education resources recommendation in universities.
Artificial spin ice has been the subject of extensive investigation in the last few years due to advances in nanotechnology and characterization techniques. So far, most of the studies have been ...limited to local probe of small area magnetic elements due to limitations with lithographic techniques used. In this study, large area spin ice and anti‐spin ice Ni80Fe20 structures with three lattice configurations have been fabricated using deep ultraviolet lithography at 193 nm exposure wavelength. The static and dynamic properties are systematically characterized using vibrating sample magnetometer, magnetic force microscopy, and broadband ferromagnetic resonance spectroscopy. Intriguing static and dynamic behaviors are observed due to the geometrical arrangement of the nanomagnets in the lattice. When the nanomagnets are saturated at high field, multiple resonance peaks whose frequencies are strongly dependent on the orientation of the applied magnetic field are observed. The experimental results are in qualitative agreement with the micromagnetic simulations. These findings may find application in the design of magnetically controlled tunable microwave filters.
The nanofabrication of large area artificial spin ice and anti‐spin ice structures by using deep ultraviolet lithography at 193 nm exposure wavelength is reported. The method allows to arrange the magnetic elements in three different lattice configurations. It is demonstrated that the static and dynamic behaviors of these structures are highly tunable. The results are validated using micromagnetic simulations.
A high-efficiency concurrent dual-band GaN power amplifier (PA) is designed and fabricated based on the network parameter extraction (NPE) method, where the expanded optimum load impedance spaces of ...continuous modes are applied to construct the NPE criteria to facilitate harmonic tuning. A swallow-spit process is proposed to improve the effectiveness of NPE by dynamically changing the criteria. The prototype design process verified that the proposed algorithm is easy to be implemented, which avoids the cumbersome tunings and complex numerical derivations on the parameters of the dual-band output matching networks. Measurement results demonstrate that the fabricated GaN PA achieves saturated output powers of 40.5 dBm ± 0.4 dBm and 41 dBm ± 0.3 dBm over dual bands of 0.6-0.8 GHz and 1.6-1.9 GHz with peak PAEs of 71%-74% and 68%-73%, respectively.
A recent analysis by the LHCb Collaboration suggests the existence of three narrow pentaquarklike states-the P_{c}(4312), P_{c}(4440), and P_{c}(4457)-instead of just one in the previous analysis the ...P_{c}(4450). The closeness of the P_{c}(4312) to the Dover ¯Σ_{c} threshold and the P_{c}(4440) and P_{c}(4457) to the Dover ¯^{*}Σ_{c} threshold suggests a molecular interpretation of these resonances. We show that these three pentaquarklike resonances can be naturally accommodated in a contact-range effective field theory description that incorporates heavy-quark spin symmetry. This description leads to the prediction of all the seven possible S-wave heavy antimeson-baryon molecules that is, there should be four additional molecular pentaquarks in addition to the P_{c}(4312), P_{c}(4440), and P_{c}(4457), providing the first example of a heavy-quark spin symmetry molecular multiplet that is complete. If this is confirmed, it will not only give us an impressive example of the application of heavy-quark symmetries and effective field theories in hadron physics, it will also uncover a clear and powerful ordering principle for the molecular spectrum, reminiscent of the SU(3)-flavor multiplets to which the light hadron spectrum conforms.
Inspired by the recent discovery of a doubly charmed tetraquark state Tcc+ by the LHCb Collaboration, we employ the effective Lagrangian approach to investigate the decay width of Tcc+→D+D0π0/D0D0π+ ...and Tcc+→D0D+γ with the assumption that Tcc+ is an isoscalar DD⁎ molecule. We show that both the Tcc→DDπ and Tcc→DDγ modes contribute to the decay width of Tcc, with the former being dominant. The resulting total decay width of about Γ=63 keV is smaller than the experimental decay width obtained from the Breit-Wigner fit of the LHCb data, Γ=410±165±43−38+18 keV, while close to the number obtained from the alternative unitary analysis, Γ=48±2−14+0 keV, which supports the molecular nature of Tcc.
Although gemcitabine-based chemotherapy has been established as a core multimodal therapy for non-small cell lung cancer (NSCLC) treatment, its clinical efficacy remains limited by the development of ...acquired resistance following tumor metastasis and relapse. In this study, we investigated how gemcitabine-resistant (GR) cells contribute to the development of NSCLC tumor malignancy via exosome-mediated transfer of microRNAs.
We first studied the mechanism of exosome internalization via PKH-67 staining and an immunofluorescence assay, then confirmed our finding by transmission electron microscopy and western blot analysis. Candidate miRNAs were identified through microarray analysis. Thereafter, RT-PCR, MTS, Transwell and soft agar assays were performed to assess the role of exosomic miR-222-3p in vitro. A 3' untranslated region reporter assay was applied to identify the target of miR-222-3p. A lung metastasis mouse model was constructed to evaluate tumor growth and metastasis in vivo. Finally, clinical samples were used for correlation analysis between exosomic miR-222-3p levels and patients' response to gemcitabine.
A549-GR-derived exosomes were internalized by receipt cells via caveolin- and lipid raft-dependent endocytosis, which allowed the transfer of miR-222-3p. Exosomic miR-222-3p enhanced the proliferation, gemcitabine resistance, migration, invasion, and anti-anoikis of parental sensitive cells by directly targeting the promoter of SOCS3. In addition, a higher level of exosomic miR-222-3p in sera usually predicted worse prognosis in NSCLC patients.
Our data demonstrate that exosomic-miR-222-3p functions as a principal regulator of gemcitabine resistance and malignant characteristics by targeting SOCS3. The exosomic miR-222-3p level in sera may be a potential prognostic biomarker for predicting gemcitabine sensitivity in NSCLC patients.
The chain sequence of a poly(styrene‐co‐methyl acrylate) copolymer is designed to form a V‐shaped gradient sequence via controlled/living radical emulsion copolymerization. This specially designed ...chain sequence gives this common copolymer the capacity of multishape memory. The copolymer can sequentially recover to its permanent shape from three or more previously programmed temporary shapes with the stimulus of temperature.
The
D
(
∗
)
Ξ
cc
(
∗
)
system and
Ξ
¯
cc
(
∗
)
Ξ
cc
(
∗
)
system can be related to the
D
(
∗
)
D
¯
(
∗
)
system via heavy anti-quark di-quark symmetry (HADS). In this work, we employ a contact-range ...effective field theory to systematically investigate the likely existence of molecules in these systems in terms of the hypothesis that X(3872) is a
1
+
+
D
D
¯
∗
bound state in the isospin symmetry limit, with some of the unknown low energy constants estimated using the light-meson saturation approximation. In the meson–meson system, a
J
PC
=
2
+
+
D
¯
∗
D
∗
molecule commonly referred to as
X
(4013) is reproduced, which is the heavy quark spin partner of
X
(3872). In the meson-baryon system, we predict two triply charmed pentaquark molecules,
J
P
=
1
/
2
-
D
∗
Ξ
cc
and
J
P
=
5
/
2
-
D
∗
Ξ
cc
∗
. In the baryon-baryon system, there exist seven di-baryon molecules,
J
PC
=
0
-
+
Ξ
¯
cc
Ξ
cc
,
J
PC
=
1
-
-
Ξ
¯
cc
Ξ
cc
,
J
PC
=
1
-
+
Ξ
¯
cc
Ξ
cc
∗
,
J
PC
=
1
-
-
Ξ
¯
cc
Ξ
cc
∗
,
J
PC
=
2
-
+
Ξ
¯
cc
Ξ
cc
∗
,
J
PC
=
2
-
+
Ξ
¯
cc
∗
Ξ
cc
∗
, and
J
PC
=
3
-
-
Ξ
¯
cc
∗
Ξ
cc
∗
. Among them, the
J
PC
=
0
-
+
Ξ
¯
cc
Ξ
cc
molecule may contribute to the
X
(7200) state recently observed by the LHCb Collaboration, which implies that
X
(7200) can be related to
X
(3872) via HADS. As a byproduct, with the heavy quark flavor symmetry we also study likely existence of molecular states in the
B
(
∗
)
B
¯
(
∗
)
,
B
¯
(
∗
)
Ξ
bb
(
∗
)
, and
Ξ
¯
bb
(
∗
)
Ξ
bb
(
∗
)
systems.
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