Renal fibrosis, especially tubulointerstitial fibrosis, is the inevitable outcome of all progressive chronic kidney diseases (CKDs) and exerts a great health burden worldwide. For a long time, ...interests in renal fibrosis have been concentrated on fibroblasts and myofibroblasts. However, in recent years, growing numbers of studies have focused on the role of tubular epithelial cells (TECs). TECs, rather than a victim or bystander, are probably a neglected mediator in renal fibrosis, responding to a variety of injuries. The maladaptive repair mechanisms of TECs may be the key point in this process. In this review, we will focus on the role of TECs in tubulointerstitial fibrosis. We will follow the fate of a tubular cell and depict the intracellular changes after injury. We will then discuss how the repair mechanism of tubular cells becomes maladaptive, and we will finally discuss the intercellular crosstalk in the interstitium that ultimately proceeds tubulointerstitial fibrosis.
The massive spread of digital misinformation has been identified as a major threat to democracies. Communication, cognitive, social, and computer scientists are studying the complex causes for the ...viral diffusion of misinformation, while online platforms are beginning to deploy countermeasures. Little systematic, data-based evidence has been published to guide these efforts. Here we analyze 14 million messages spreading 400 thousand articles on Twitter during ten months in 2016 and 2017. We find evidence that social bots played a disproportionate role in spreading articles from low-credibility sources. Bots amplify such content in the early spreading moments, before an article goes viral. They also target users with many followers through replies and mentions. Humans are vulnerable to this manipulation, resharing content posted by bots. Successful low-credibility sources are heavily supported by social bots. These results suggest that curbing social bots may be an effective strategy for mitigating the spread of online misinformation.
The separation of racemic compounds is important in many fields, such as pharmacology and biology. Taking advantage of the intrinsically strong chiral environment and specific interactions featured ...by biomolecules, here we contribute a general strategy is developed to enrich chirality into covalent organic frameworks (COFs) by covalently immobilizing a series of biomolecules (amino acids, peptides, enzymes) into achiral COFs. Inheriting the strong chirality and specific interactions from the immobilized biomolecules, the afforded biomolecules⊂COFs serve as versatile and highly efficient chiral stationary phases towards various racemates in both normal and reverse phase of high‐performance liquid chromatography (HPLC). The different interactions between enzyme secondary structure and racemates were revealed by surface‐enhanced Raman scattering studies, accounting for the observed chiral separation capacity of enzymes⊂COFs.
COF chirality: A general and efficient strategy has been developed to introduce chirality into covalent organic frameworks (COFs) by covalently immobilizing biomolecules into achiral COFs. The biomolecules⊂COFs can serve as chiral stationary phases for efficient chiral separation of a broad range of racemates.
We modify a nickel-rich layered LiNi0.8Co0.1Mn0.1O2 (NCM811) positive electrode material by substituting the transition metals with Zr to mitigate its structural instability and capacity degradation. ...We show that Zr, over a concentration range of 0.5–5.0 at.%, can simultaneously reside on and expand the lattice of NCM811 and form Li-rich lithium zirconates on their surfaces. In particular, Li(Ni0.8Co0.1Mn0.1)0.99Zr0.01O2 (1% Zr-NCM811) exhibits the best rate capability among all the compositions in this study. It shows higher cycling durability than the raw NCM811 at both low and high current density lithiation and de-lithiation. According to X-ray photoelectron spectroscopy and cyclic voltammetry measurements, the 1% Zr-NCM811 sample is more chemically/electrochemically stable than the raw. In addition to comparing the diffusivities in the coin-cell measurements, we demonstrate that Zr modification can facilitate Li-ion diffusion in the NCM811 balk material by direct-current polarization measurements. The superior performance of Zr-NCM811 results from the lattice expansion induced by Zr doping and the presence of ion-conducting lithium zirconates partially coated on the surface of Zr-NCM811 particles.
•1% Zr-NCM811 witnesses largely improved cycling stability and rate capability.•Zr modification realizes bulk Zr doping and surface zirconate coating simultaneously.•Zr modification increases the Li-ion diffusivity of bulk NCM811.
A
bstract
The lifetimes of bottom and charmed hadrons are analyzed within the framework of the heavy quark expansion (HQE). Lifetime differences arise from the spectator effects such as weak
W
...-annihilation and Pauli interference. Spectator effects originating from dimension-7 four-quark operators are derived. Hadronic matrix elements of four-quark operators are parameterized in a model-independent way. Using the dimension-6 bag parameters recently determined from HQET sum rules and the vacuum insertion approximation for meson matrix elements of dimension-7 operators, the calculated
B
meson lifetime ratios
τ
(
B
+
)/
τ
(
B
d
0
) = 1.074
− 0.016
+ 0.017
and
τ
(
B
s
0
)/
τ
(
B
d
0
) = 0.9962 ± 0.0024 are in excellent agreement with experiment. Likewise, based on the quark model evaluation of baryon matrix elements, the resulting baryon lifetime ratios
τ
(Ξ
b
−
)/
τ
(Λ
b
0
),
τ
(Ξ
b
−
)/
τ
(
Ξ
b
0
),
τ
(Ω
b
−
)/
τ
(
Ξ
b
−
) and the Λ
b
−
B
0
lifetime ratio
τ
(Λ
b
0
)/
τ
(
B
d
0
) = 0.953 also agree well with the data. Contrary to the bottom hadron sector where the HQE in 1/
m
b
works well, the HQE to 1/
m
c
3
fails to give a satisfactory description of the lifetimes of both charmed mesons and charmed baryons. This calls for the subleading 1/
m
Q
corrections to spectator effects. The relevant dimension-7 spectator effects are in the right direction for explaining the large lifetime ratio of
τ
(Ξ
c
+
)/
τ
(Λ
c
+
). However, the destructive 1/
m
c
corrections to Γ(Ω
c
0
) are too large to justify the validity of the HQE, namely, the predicted Pauli interference and semileptonic rates for Ω
c
0
become negative. Demanding these rates to be positive for a sensible HQE, we find the lifetime pattern
τ
(Ξ
c
+
) >
τ
(
Ω
c
0
) >
τ
(Λ
c
+
) >
τ
(Ξ
c
0
), contrary to the current hierarchy
τ
(Ξ
c
+
) >
τ
(Λ
c
+
) >
τ
(Ξ
c
0
) >
τ
(
Ω
c
0
). We conclude that the Ω
c
0
, which is naively expected to be shortest-lived in the charmed baryon system owing to the large constructive Pauli interference, could live longer than the Λ
c
+
due to the suppression from 1/
m
c
corrections arising from dimension-7 four-quark operators. The new charmed baryon lifetime pattern needs to be tested in forthcoming experiments.
Covalent organic frameworks (COFs), which are built upon dynamic covalent chemistry (DCC) with various organic building blocks, possess predesignable, highly ordered and crystalline porous ...structures. These features endow COFs with great potential in the development of function‐tailored materials, particularly in catalytic organic synthesis. Start from selective oxidation reactions early introduced by Ferdi, Thomas and their co‐workers, and then Wang and co‐workers performed Suzuki‐Miyaura reaction through integrating palladium into COFs, increasing numbers of works were established to explore their potentials in the 4.5catalysis of organic reactions. As heterogeneous organic catalysts, COFs bring benefits and solve problems, but also create new obstacles. Hence, we would like to establish a comprehensive system to review some pioneering works in this area. This will help us get a better view so that we can discuss the key and challenging issues we are currently confronted with.
Membranes are recognized as a key component in many environment and energy‐related applications, but conventional membranes are challenged to satisfy the growing demand for ever more energy‐efficient ...processes. Janus membranes, a novel class with asymmetric properties on each side, have recently emerged and represent enticing opportunities to address this challenge. With an inner driving force arising from their asymmetric configuration, Janus membranes are appealing for enhancing energy efficiency in a variety of membrane processes by promoting the desired transport. Here, the fundamental principles to prepare Janus membranes with asymmetric surface wettability and charges are summarized, and how they work in conventional and unconventional membrane processes is demonstrated.
The rise of Janus membranes brings new opportunities to tackle challenges surrounding energy management, while also enabling novel functions that are not even viable when using conventional membranes.
Although the function of the BRCA1 gene has been extensively studied, the relationship between BRCA1 gene expression and tumor aggressiveness remains controversial in sporadic breast cancers. Because ...the BRCA1 protein is known to regulate estrogen signaling, we selected microarray data of ER
breast cancers from the GEO public repository to resolve previous conflicting findings. The BRCA1 gene expression level in highly proliferative luminal B tumors was shown to be higher than that in luminal A tumors. Survival analysis using a cure model indicated that patients of early ER
breast cancers with high BRCA1 expression developed rapid distant metastasis. In addition, the proliferation marker genes MKI67 and PCNA, which are characteristic of aggressive tumors, were also highly expressed in patients with high BRCA1 expression. The associations among high BRCA1 expression, high proliferation marker expression, and high risk of distant metastasis emerged in independent datasets, regardless of tamoxifen treatment. Tamoxifen therapy could improve the metastasis-free fraction of high BRCA1 expression patients. Our findings link BRCA1 expression with proliferation and possibly distant metastasis via the ER signaling pathway. We propose a testable hypothesis based on these consistent results and offer an interpretation for our reported associations.
The first two Medium Earth Orbit (MEO) satellites of the third generation of BeiDou satellite navigation System (BDS-3) were successfully launched on November 5, 2017. This historical launch starts ...the new era of the global navigation satellite system of BeiDou. Before the first two satellites of BDS-3, a demonstration system for BDS-3 with five satellites, including two Inclined Geosynchronous Orbit satellites (IGSO) and three MEO satellites, was established between 2015 and 2016 for testing the new payloads, new designed signals and new techniques. In the demonstration system, the new S frequency signal and satellite hydrogen clock as well as inter-satellite link (ISL) based on Ka-band signals with time-division multiple addresses (TDMA) were tested. This paper mainly analyzes the performances of the demonstration system, including the signalto- noise ratios, pseudorange errors and the multipath errors of the civilian signals of BDS-3. The qualities of signals in space, time synchronization and timing precision were tested as well. Most of the performances were compared with those of the regional BeiDou satellite navigation system (BDS-2). At last, the performances of positioning, navigation and timing (PNT) of the future BeiDou global system (BDS-3) were evaluated based on the signal quality of the present demonstration satellite system.
Taiwan's National Health Insurance Research Database (NHIRD) exemplifies a population-level data source for generating real-world evidence to support clinical decisions and health care policy-making. ...Like with all claims databases, there have been some validity concerns of studies using the NHIRD, such as the accuracy of diagnosis codes and issues around unmeasured confounders. Endeavors to validate diagnosed codes or to develop methodologic approaches to address unmeasured confounders have largely increased the reliability of NHIRD studies. Recently, Taiwan's Ministry of Health and Welfare (MOHW) established a Health and Welfare Data Center (HWDC), a data repository site that centralizes the NHIRD and about 70 other health-related databases for data management and analyses. To strengthen the protection of data privacy, investigators are required to conduct on-site analysis at an HWDC through remote connection to MOHW servers. Although the tight regulation of this on-site analysis has led to inconvenience for analysts and has increased time and costs required for research, the HWDC has created opportunities for enriched dimensions of study by linking across the NHIRD and other databases. In the near future, researchers will have greater opportunity to distill knowledge from the NHIRD linked to hospital-based electronic medical records databases containing unstructured patient-level information by using artificial intelligence techniques, including machine learning and natural language processes. We believe that NHIRD with multiple data sources could represent a powerful research engine with enriched dimensions and could serve as a guiding light for real-world evidence-based medicine in Taiwan.
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