This letter presents a detailed performance analysis of the intelligent reflecting surface (IRS) aided single-input single-output communication systems, taking into account of the direct link between ...the transmitter and receiver. A closed-form upper bound is derived for the ergodic capacity, and an accurate approximation is obtained for the outage probability. In addition, simplified expressions are presented in the asymptotic regime. Numerical results are provided to validate the correctness of the theoretical analysis. It is found that increasing the number of reflecting elements can significantly boost the ergodic capacity and outage probability performance, and a strong line-of-sight component is also beneficial. In addition, it is desirable to deploy the IRS close to the transmitter or receiver, rather than in the middle.
Drug delivery by nanocarriers (NCs) has long been stymied by dominant liver uptake and limited target organ deposition, even when NCs are targeted using affinity moieties. Here we report a universal ...solution: red blood cell (RBC)-hitchhiking (RH), in which NCs adsorbed onto the RBCs transfer from RBCs to the first organ downstream of the intravascular injection. RH improves delivery for a wide range of NCs and even viral vectors. For example, RH injected intravenously increases liposome uptake in the first downstream organ, lungs, by ~40-fold compared with free NCs. Intra-carotid artery injection of RH NCs delivers >10% of the injected NC dose to the brain, ~10× higher than that achieved with affinity moieties. Further, RH works in mice, pigs, and ex vivo human lungs without causing RBC or end-organ toxicities. Thus, RH is a clinically translatable platform technology poised to augment drug delivery in acute lung disease, stroke, and several other diseases.
A
bstract
Sum rules for structure functions and their twist-2 relations have important roles in constraining their magnitudes and
x
dependencies and in studying higher-twist effects. The ...Wandzura-Wilczek (WW) relation and the Burkhardt-Cottingham (BC) sum rule are such examples for the polarized structure functions
g
1
and
g
2
. Recently, new twist-3 and twist-4 parton distribution functions were proposed for spin-1 hadrons, so that it became possible to investigate spin-1 structure functions including higher-twist ones. We show in this work that an analogous twist-2 relation and a sum rule exist for the tensor-polarized parton distribution functions
f
1
LL
and
f
LT
, where
f
1
LL
is a twist-2 function and
f
LT
is a twist-3 one. Namely, the twist-2 part of
f
LT
is expressed by an integral of
f
1
LL
(or
b
1
) and the integral of the function
f
2
LT
= (2
/
3)
f
LT
− f
1
LL
over
x
vanishes. If the parton-model sum rule for
f
1
LL
(
b
1
) is applied by assuming vanishing tensor-polarized antiquark distributions, another sum rule also exists for
f
LT
itself. These relations should be valuable for studying tensor-polarized distribution functions of spin-1 hadrons and for separating twist-2 components from higher-twist terms, as the WW relation and BC sum rule have been used for investigating
x
dependence and higher-twist effects in
g
2
. In deriving these relations, we indicate that four twist-3 multiparton distribution functions
F
LT
,
G
LT
,
H
LL
⊥
, and
H
TT
exist for tensor-polarized spin-1 hadrons. These multiparton distribution functions are also interesting to probe multiparton correlations in spin-1 hadrons. In the near future, we expect that physics of spin-1 hadrons will become a popular topic, since there are experimental projects to investigate spin structure of the spin-1 deuteron at the Jefferson Laboratory, the Fermilab, the nuclotron-based ion collider facility, the electron-ion colliders in US and China in 2020’s and 2030’s.
We study the energy-momentum tensor of spin-0 and spin-12 hadrons in momentum space. We parametrize this object in terms of so-called gravitational transverse-momentum distributions, and we identify ...in the quark sector the relations between the latter and the usual transverse-momentum distributions. Focusing on particular components of the energy-momentum tensor, we study momentum densities, flux of inertia and stress distribution in momentum space, revealing part of the wealth of physical information that can be gained from higher-twist transverse-momentum distributions.
Structure functions of polarized spin-1 hadrons will be measured at various accelerator facilities in the near future. Recently, transverse-momentum-dependent and collinear parton distribution ...functions were theoretically proposed at twist 3 and twist 4 in addition to the twist-2 ones, so that full investigations became possible for structure functions of spin-1 hadrons in the same level with those of the spin-1/2 nucleons. Furthermore, twist-3 tensor-polarized multiparton distribution functions were also recently found for spin-1 hadrons. In this work, we show relations among the collinear parton- and multiparton-distribution functions for spin-1 hadrons by using equation of motion for quarks. These relations are valuable in constraining the distribution functions and learning about multiparton correlations in spin-1 hadrons.
Programmed cell death protein-1 (PD-1)/programmed cell death ligand-1 (PD-L1) interaction plays a crucial role in tumor-associated immune escape. Here, we verify that triple-negative breast cancer ...(TNBC) has higher PD-L1 expression than other subtypes. We then discover that nucleophosmin (NPM1) binds to PD-L1 promoter specifically in TNBC cells and activates PD-L1 transcription, thus inhibiting T cell activity in vitro and in vivo. Furthermore, we demonstrate that PARP1 suppresses PD-L1 transcription through its interaction with the nucleic acid binding domain of NPM1, which is required for the binding of NPM1 at PD-L1 promoter. Consistently, the PARP1 inhibitor olaparib elevates PD-L1 expression in TNBC and exerts a better effect with anti-PD-L1 therapy. Together, our research has revealed NPM1 as a transcription regulator of PD-L1 in TNBC, which could lead to potential therapeutic strategies to enhance the efficacy of cancer immunotherapy.
Long noncoding RNAs (lncRNAs) affect gene expression through a wide range of mechanisms and are considered as important regulators in many essential biological processes. A large number of lncRNA ...transcripts have been predicted or identified in plants in recent years. However, the biological functions for most of them are still unknown. In this study, we identified an Arabidopsis (Arabidopsis thaliana) lncRNA, DROUGHT INDUCED lncRNA (DRIR), as a novel positive regulator of the plant response to drought and salt stress. DRIR was expressed at a low level under nonstress conditions but can be significantly activated by drought and salt stress as well as by abscisic acid (ABA) treatment. We identified a T-DNA insertion mutant, drirᴰ, which had higher expression of the DRIR gene than the wild-type plants. The drirᴰ mutant exhibits increased tolerance to drought and salt stress. Overexpressing DRIR in Arabidopsis also increased tolerance to drought and salt stress of the transgenic plants. The drirᴰ mutant and the overexpressing seedlings are more sensitive to ABA than the wild type in stomata closure and seedling growth. Genome-wide transcriptome analysis demonstrated that the expression of a large number of genes was altered in drirᴰ and the overexpressing plants. These include genes involved in ABA signaling, water transport, and other stress-relief processes. Our study reveals a mechanism whereby DRIR regulates the plant response to abiotic stress by modulating the expression of a series of genes involved in the stress response.
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