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.
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.
Since December 2019, when coronavirus disease 2019 (Covid-19) emerged in Wuhan city and rapidly spread throughout China, data have been needed on the clinical characteristics of the affected ...patients.
We extracted data regarding 1099 patients with laboratory-confirmed Covid-19 from 552 hospitals in 30 provinces, autonomous regions, and municipalities in mainland China through January 29, 2020. The primary composite end point was admission to an intensive care unit (ICU), the use of mechanical ventilation, or death.
The median age of the patients was 47 years; 41.9% of the patients were female. The primary composite end point occurred in 67 patients (6.1%), including 5.0% who were admitted to the ICU, 2.3% who underwent invasive mechanical ventilation, and 1.4% who died. Only 1.9% of the patients had a history of direct contact with wildlife. Among nonresidents of Wuhan, 72.3% had contact with residents of Wuhan, including 31.3% who had visited the city. The most common symptoms were fever (43.8% on admission and 88.7% during hospitalization) and cough (67.8%). Diarrhea was uncommon (3.8%). The median incubation period was 4 days (interquartile range, 2 to 7). On admission, ground-glass opacity was the most common radiologic finding on chest computed tomography (CT) (56.4%). No radiographic or CT abnormality was found in 157 of 877 patients (17.9%) with nonsevere disease and in 5 of 173 patients (2.9%) with severe disease. Lymphocytopenia was present in 83.2% of the patients on admission.
During the first 2 months of the current outbreak, Covid-19 spread rapidly throughout China and caused varying degrees of illness. Patients often presented without fever, and many did not have abnormal radiologic findings. (Funded by the National Health Commission of China and others.).
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.
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.
Six well‐defined examples of ortho‐(4,4′‐dichlorobenzhydryl)‐substituted 2,6‐diaryliminopyridine‐cobalt dichloride complex, Co1−Co6, have been prepared in reasonable yield by treatment of the ...corresponding free ligand (L1−L6) with cobalt(II) chloride hexahydrate. The molecular structures of Co2 and Co3 highlight their pseudo‐square pyramidal geometry, the nonsymmetrical properties of the N,N,N′‐chelating ligand and the steric shielding conferred by the ortho‐(4,4′‐dichlorobenzhydryl) groups. On treatment with the aluminoxanes, MAO or MMAO, all cobalt complexes exhibited good to high productivities for ethylene polymerization (up to 8.96×106 g (PE) mol−1 (Co) h−1 at 60 °C) affording linear polyethylene with molecular weights in the range 28.8–250.2 kg mol−1. The steric properties of the ortho‐substituents were found to exhibit significant effects on the activity and molecular weight of the resulting polymers. For example, Co1/MAO proved the most active and thermally stable, while the more sterically encumbered Co3 in combination with either MAO or MMAO afforded the highest molecular weight polymer. All polymerizations were well‐controlled as is evidenced by the narrow dispersities displayed by the polymers, a feature that is characteristic of single‐site behavior. By comparison with their ortho‐benzhydryl‐substituted cobalt counterparts, the effect of the para‐chloride substitution was to increase thermal stability, raise activity and depress polymer molecular weight.
Well‐controlled cobalt polymerization catalysts appended with (p‐ClPh)2CH groups can attain their optimal performance at temperatures of 60 °C forming linear polyethylenes with a wide range in molecular weights.
The concept of the OOS of spacecraft can be traced back to the 1960s, when the main focus was on providing the necessary maintenance to advance the lifetime of spacecraft and extending the scale and ...function through on-orbit assembly. During the past decades, the Hubble Space Telescope has made great contributions to the fields of astronomy and physics through both observational data and the success of five OOS missions to overcome big challenges. That included an initial flaw of its primary mirror and subsequent obstacles associated with replacing and upgrading its science instruments. Furthermore, many programs have been carried out in the area of the OOS of spacecraft with successful operations in space. It could be exemplified by the assembly of the International Space Station, service verification of ETS-VII and Orbital Express, and detailed research for future applications including servicer and client satellites and particularly large space systems. This paper attempts to summarize all reported programs of the OOS in terms of engineering developments and provide an overall perspective for investigators in this field. Based on the reviewed programs, an analysis is carried out to elucidate the logical architectures of the mission and technology of the OOS of spacecraft. Further attention is paid to discussions of the enabling technologies that support the development of the OOS and related spacecraft. As an outlook, the future development and challenges of the OOS and the application of novel technologies are finally discussed to extend the present review work.
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.
Photovoltaic power‐conversion systems can harvest energy from sunlight almost perpetually whenever sunrays are accessible. Meanwhile, as indispensable energy storage units used in advanced ...technologies such as portable electronics, electric vehicles, and renewable/smart grids, batteries are energy‐limited closed systems and require constant recharging. Fusing these two essential technologies into a single device would create a sustainable power source. Here, it is demonstrated that such an integrated device can be realized by fusing a rear‐illuminated single‐junction perovskite solar cell with Li4Ti5O12‐LiCoO2 Li‐ion batteries, whose photocharging is enabled by an electronic converter via voltage matching. This design facilitates a straightforward monolithic stacking of the battery on the solar cell using a common metal substrate, which provides a robust mechanical isolation between the two systems while simultaneously providing an efficient electrical interconnection. This system delivers a high overall photoelectric conversion‐storage efficiency of 7.3%, outperforming previous efforts on stackable integrated architectures with organic–inorganic photovoltaics. Furthermore, converter electronics facilitates system control with battery management and maximum power point tracking, which are inevitable for efficient, safe, and reliable operation of practical loads. This work presents a significant advancement toward integrated photorechargeable energy storage systems as next‐generation power sources.
A simple yet efficient hybrid photorechargeable design is presented, which consists of a monolithic integration of perovskite solar cell and lithium ion battery enabled by an electronic converter and demonstrates an overall photoelectric conversion‐storage efficiency of 7.3%.
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