High‐quality MOF thin films with high orientation and controlled thickness are extremely desired for applications. However, they have been only successfully fabricated on flat substrates. Those MOF ...2D thin films are limited by low exposed area and slow mass transport. To overcome these issues, MOF 3D thin films with good crystallinity, preferred orientation, and precisely controllable thickness in nanoscale were successfully prepared in a controllable layer‐by‐layer manner on nanowire array substrate for the first time. The as‐prepared Cu‐HHTP 3D thin film is superior to corresponding 2D thin films and showed one of the highest sensitivity, lowest LOD, and fastest response among all reported chemiresistive NH3 sensing materials at RT. This work provides a feasible approach to grow preferred‐oriented 3D MOF thin film, offering new perspectives for constructing MOF‐based heterostructures for advanced applications.
Semiconducting MOF 3D thin films with good crystallinity, preferred orientation, as well as precisely controllable thickness in nanoscale were successfully prepared in a layer‐by‐layer manner on a nanowire array substrate. Compared to 2D thin films, the Cu‐HHTP 3D thin film shows one of the highest sensitivity, lowest LOD and fastest response speed among all reported chemiresistive NH3 sensing materials at RT.
We truly appreciate the comments from C.E. Leiva Sisnieguez and colleagues, who have performed a further analysis on the potential association between cardiovascular comorbidities and the clinical ...outcomes of coronavirus disease 2019 (COVID-19), particularly the mortality). We also applaud the suggestion to thoroughly adjust for potential confounding factors when interpreting the association between specific categories of cardiovascular comorbidities (
e.g.
hypertension) and the clinical outcomes of COVID-19. To this end, we have attempted to incorporate the cardiovascular diseases (including coronary heart disease) into the multivariate regression model 1. Findings of the model indicated a prominent collinearity between hypertension and coronary heart disease, and we have therefore elected to retain hypertension in the regression model for further analyses.
Comorbid hypertension correlates with poorer outcomes in patients with COVID-19
https://bit.ly/2zoT9f0
In recent years, hybrid perovskite solar cells (HPSCs) have received considerable research attention due to their impressive photovoltaic performance and low‐temperature solution processing ...capability. However, there remain challenges related to defect passivation and enhancing the charge carrier dynamics of the perovskites, to further increase the power conversion efficiency of HPSCs. In this work, the use of a novel material, phenylhydrazinium iodide (PHAI), as an additive in MAPbI3 perovskite for defect minimization and enhancement of the charge carrier dynamics of inverted HPSCs is reported. Incorporation of the PHAI in perovskite precursor solution facilitates controlled crystallization, higher carrier lifetime, as well as less recombination. In addition, PHAI additive treated HPSCs exhibit lower density of filled trap states (1010 cm−2) in perovskite grain boundaries, higher charge carrier mobility (≈11 × 10−4 cm2 V−1 s), and enhanced power conversion efficiency (≈18%) that corresponds to a ≈20% improvement in comparison to the pristine devices.
A novel material called phenylhydrazinium iodide (PHAI) is effective for defects minimization, surface passivation, and efficient charge transportation in hybrid perovskite solar cells. It plays multiple roles in controlled crystallization, stabilizing under‐coordinated ions, and as a self‐supported moisture barrier in perovskite films.
In this study, researchers describe the clinical characteristics of coronavirus disease 2019 in a selected cohort of 1099 patients with laboratory-confirmed disease throughout mainland China during ...the first 2 months of the current outbreak.
Coordination reaction of a known three-dimensional (3D) polymer precursor {Na3Na9(Cbdcp)6(H2O)18}n (A, Cbdcp = N-(4-carboxybenzyl)-(3,5-dicarboxyl)pyridinium) with Zn(NO3)2·6H2O in H2O or H2O/DMF at ...100 °C and in the presence of aspirin, 5-fluorouracil (5-FU) as modulators, trans-1,2-bis(4-pyridyl)ethylene (bpe) or 1,2-bis(4-pyridyl)ethane (bpea) as ancillary ligands afforded six novel Zn(II)-based metal-organic frameworks (MOFs), that is, {Zn(Cbdcp)(H2O)3·H2O}n (1, 1D zigzag chain), {Zn(HCbdcp)2·H2O}n (2, 2D sheet), {Zn(Cbdcp)(bpe)1/2·2H2O}n (3, 3D polymer), {Zn(Cbdcp)(bpe)1/2·2H2O}n (4, 2D network), {Zn(Cbdcp)(bpea)1/2·2H2O}n (5, 3D polymer) and {Zn(Cbdcp)(bpea)1/2·2H2O}n (6, 2D network). Among them, compound 2 contains aromatic rings, positively charged pyridinium, Zn2+ cation centers and carboxylic acid groups lined up on the 2D sheet structure with a certain extended surface exposure. The unique structure of 2 facilitates effective association with carboxyfluorescein (FAM) labeled probe single stranded DNA (probe ss-DNA, delineates as P-DNA) to yield a P-DNA@2 system, and leads to fluorescence quenching of FAM via a photoinduced electron transfer process. The P-DNA@2 system is effective and reliable for the detection of human immunodeficiency virus 1 ds-DNA (HIV ds-DNA) sequences and capable of distinguishing complementary HIV ds-DNA from mismatched target sequences with the detection limit as low as 10 pM (S/N = 3).
Six water-stable zinc(II) zwitterionic carboxylate compounds with 1D chain, 2D and 3D networks were synthesized. Compound 2 can interact with the probe DNA through noncovalent bonds to form P-DNA@2 system. This system can be used as an effective, fluorescent sensing platform for the detection of HIV ds-DNA with the detection limit as low as 10 pM. Display omitted
•Six water-stable zinc(II) zwitterionic carboxylate compounds with 1D chain, 2D and 3D networks were synthesized.•Compound 2 can interact with the probe DNA through noncovalent bonds to form P-DNA@2 system.•A Zinc(II)-based MOF can interact with the probe DNA to form a system, which can be used for the detection of HIV ds-DNA.
The Cuonadong deposit is located in southern Tibet and represents the first large-scale tin polymetallic deposit in the Himalayan region. Sn-(W) skarn mineralization is spatially related to ...leucogranites, whereas Be-Nb-Ta mineralization mainly develops in pegmatites. Alteration and veining in this deposit can be divided in to five stages: prograde skarn (stage I), retrograde skarn (stage II), cassiterite-quartz vein (stage III), cassiterite-sulfide vein (stage IV) and fluorite quartz vein (stage V). 40Ar39Ar dating of muscovite from the skarn and phlogopite from the cassiterite-sulfide vein yield isochron ages of 15.4 ± 0.3 Ma and 15.0 ± 0.3 Ma, respectively, whereas UPb dating of cassiterite from the skarn yields a Tera-Wasserburg low-intercept precise age of 14.2 ± 0.2 Ma. Zircon and monazite UPb ages of the causative stanniferous leucogranites are 15.3 ± 0.1 Ma and 14.9 ± 0.2 Ma, respectively. Mineralization ages are consistent with the emplaced ages of the granites within the analytical uncertainties, which indicates that the tin polymetallic mineralization is genetically related to the Miocene leucogranites. Sn-bearing leucogranites have zircon εHf(t) values that vary from −13.3 to −8.5 (-10.7 on average), with an average TDM2 value of 1.56 Ga, which reveals that the leucogranites are derived from partial melting of ancient metasedimentary rocks. According to the zircon trace elements, the Miocene leucogranites are highly differentiated reduced S-type granites that formed at relatively high temperature. The average homogenization temperatures of fluid inclusions in different minerals that formed at stages II, III, IV and V are 351, 315, 240 and 175 °C, respectively, whereas their salinities are 8.3, 4.9, 9.5 and 3.8 wt% NaCl equiv., respectively. The C-H-O-S-Pb isotopes indicate that the ore-forming fluid and materials mainly originated from Miocene leucogranite. Dehydration and partial melting of mica in the Greater Himalayan crystalline complex due to east-west extension at 18–14 Ma developed the stanniferous leucogranite and ore-controlling fault system. Because of the pervasive occurrence of gneiss domes and Miocene Sn-bearing leucogranites similar to Cuonadong, the Himalaya has strong potential to be a new globally important Sn-(W) rare metal metallogenic belt.
Display omitted
•Tin polymetallic mineralization dated as ca. 15 Ma.•Mineralization genetically related to fractionated Miocene leucogranites.•Ore-forming materials of crustal origin.•Himalayan leucogranites belt has great potential for Sn polymetallic ore deposits.
The application of Schottky junction in self-powered devices is limited by low efficiency in both separation and transport of photogenerated electrons/holes. This issue may be overcome by introducing ...electronically conductive metal-organic framework (EC-MOF) materials into the junction and limited by preparing high-quality thin films of EC-MOFs. In this study, for the first time, high-quality EC-MOF thin films were demonstrated as effective interlayer materials to solve the above-mentioned issue by modulating the height of Schottky barrier (
Φ
B
). The EC-MOF-based self-powered Schottky diode can act as a photodetector and demonstrate the highest external quantum efficiency (84%) for all reported self-powered photodetectors as well as the broadest detectable spectrum range (250 to 1500 nm), high on-off ratio (∼10
3
) and short rise (0.007 s) and fall time (0.03 s). Furthermore, it can be used as a gas sensor for typical harmful gases and vapors.
High-quality EC-MOF thin films are used to modulate the Schottky barrier height and detect light/gas by self-powered mode.
In this study, we designed and synthesized a novel class of 1,3,4-oxadiazolyl-containing β-carboline derivatives, i.e., compounds f1∼f35 as potential α-glucosidase inhibitors. All the synthesized ...compounds possessed outstanding α-glucosidase inhibitory activity with the IC50 values in the range of 3.07–15.49 μM, representing that they are 36∼183-fold more active than a positive control, acarbose (IC50 = 564.28 μM). Among them, compound f26 exhibited the highest α-glucosidase inhibitory activity (IC50 = 3.07 μM) and was demonstrated to function as a reversible and noncompetitive inhibitor. Mechanistic studies by means of 3D fluorescence spectra, CD spectra and molecular docking suggested that complexation of compound f26 with α-glucosidase through hydrogen bonds and hydrophobic interactions, led to changes in the conformation and secondary strictures of α-glucosidase and further the inhibition of the enzymatic activity. In vivo results showed that oral administration of compound f26 (50 mg/kg/day) could obviously reduce the levels of fasting blood glucose and improve glucose tolerance and dyslipidemia in diabetic mice. The present findings suggest that compound f26 is exploitable as a potential lead compound for the development of new α-glucosidase inhibitors with antidiabetic activity.
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•1,3,4-oxadiazolyl-containing β-carboline derivatives f1∼f35 were and synthesized.•All compounds showed potential α-glucosidase inhibitors.•The inhibition mechanism of f26 was investigated by multispectral methods.•f26 presented in vivo hypoglycemic activity in STZ-induced diabetic mice.
Cinnamic ester is a common and abundant chemical substance, which can be extracted from natural plants. Compared with traditional esters, cinnamic ester contains α,β‐unsaturated carbonyl structure ...with multiple reactive sites, resulting in more abundant reactivities and chemical structures. Here, a versatile polymerization‐induced emission (PIE) is successfully demonstrated through Barbier polymerization of cinnamic ester. Attributed to its abundant reactivities of α,β‐unsaturated carbonyl structure, Barbier polymerization of cinnamic esters with different organodihalides gives polyalcohol and polyketone via 1,2‐addition and 1,4‐addition, respectively, which is also confirmed by small molecular model reactions. Meanwhile, these organodihalides dependant polyalcohol and polyketone exhibit different non‐traditional intrinsic luminescence (NTIL) from aggregation‐induced emission (AIE) type to aggregation‐caused quenching (ACQ) type, where novel PIE luminogens (PIEgens) are revealed. Further potential applications in explosive detection are carried out, where it achieves TNT detection sensitivity at ppm level in solution and ng level on the test paper. This work therefore expands the structure and functionality libraries of monomer, polymer and NTIL, which might cause inspirations to different fields including polymer chemistry, NTIL, AIE and PIE.
Cinnamic ester was successfully used as monomer to prepare polymers with NTIL characteristics through Barbier PIE strategy, which exhibited adjustable NTIL from AIE type to ACQ type. Further potential applications and the mechanism of luminescent polymer in explosive detection were carried out.
The 4,4′-difluorobenzhydryl-modified bis(imino)pyridylferrous chlorides, 2-{CMeN(2,6-(4-FC
6
H
4
)
2
CH
2
-4-
t
-BuC
6
H
2
)}-6-(CMeNAr)C
5
H
3
N FeCl
2
(Ar = 2,6-Me
2
C
6
H
3
Fe1
, 2,6-Et
2
C
6
H
3
...Fe2
, 2,6-i-Pr
2
C
6
H
3
Fe3
, 2,4,6-Me
3
C
6
H
2
Fe4
, 2,6-Et-4-MeC
6
H
2
Fe5
and 2,6-(4-FC
6
H
4
)
2
CH
2
-4-
t
-BuC
6
H
2
Fe6
), were synthesized in good yields. All iron complexes were characterized by
1
H/
19
F NMR and elemental analysis, and the molecular structures of representative complexes
Fe1
and
Fe6
were determined by single crystal X-ray diffraction, which revealed a slightly distorted square pyramid around the iron center. Activated with either MAO or MMAO,
Fe1-Fe5
exhibited very high activities (up to 17.2 × 10
6
g (PE) mol
−1
(Fe) h
−1
for
Fe1
/MMAO) toward ethylene polymerization, producing highly linear polyethylenes with narrow dispersities as required by industry and value added PEs. Importantly, the
Fe1
/MAO maintained an activity of 9.5 × 10
6
g (PE) mol
−1
(Fe) h
−1
at 100 °C of operating temperature, making the catalytic system suitable for practical application. Simulation quantitatively revealed the mechanism of the enhanced catalytic performance from the electronic and steric point of view.
Extremely highly active and thermal-stable bis(imino)pyridine-iron precatalysts appended with (
p
-FPh)
2
CH groups were achieved in ethylene polymerization for highly linear polyethylenes with narrow distributions.
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