Publications by authors named "Yan J Li"

Although Pb-based metal halide perovskites (MHPs) have excellent photoelectric characteristics, its toxicity remains a limiting factor for its widespread application. In the paper, a series of CsCuClBr (x=1, 2, 3) MHPs microcrystals were developed and their hydrogen evolution performance in ethanol and HX (X=Cl, Br) were also studied. Among them, CsCuCl microcrystals exhibit high hydrogen evolution performance in both HX and ethanol, attributed to its longest average lifetime and suitable band structure.

View Article and Find Full Text PDF

The intrinsic spin of the electron and its associated magnetic moment can provide insights into spintronics. However, the interaction is extremely weak, as is the case with the coupling between an electron's spin and a magnetic field, and it poses significant experimental challenges. Here we demonstrate the direct measurement of polarized single NV centers and their spin-spin coupling behaviors in diamond.

View Article and Find Full Text PDF

Exploring the molecular packing and interaction between chiral molecules, no matter single enantiomer or racemates, is important for recognition and resolution of chiral drugs. However, sensitive and non-destructive analysis methods are lacking. Herein, an intermolecular-charge transfer (ICT) based spectroscopy is reported to reveal the differences in interaction between the achiral acceptor 1,2,4,5-tetracyanobenzene (TCNB) and the chiral donors, including S, R, and racemic naproxen (S/R/rac-NAP).

View Article and Find Full Text PDF

Imaging of electronic device surface or sub-surface electromagnetic fields under operating conditions is important for device design and diagnosis. In this study, we proposed a method to characterize specific magnetic field properties of electromagnetic devices at micron-scale using a solid-state quantum sensor, namely diamond nitrogen-vacancy (NV) centers. By employing a wide-field magnetic field measurement technique based on NV centers, we rapidly obtain the first-order magnetic field distribution of anomalous regions.

View Article and Find Full Text PDF

Single-atom catalysis of carbon monoxide oxidation on metal-oxide surfaces is crucial for greenhouse recycling, automotive catalysis, and beyond, but reports of the atomic-scale mechanism are still scarce. Here, using scanning probe microscopy, we show that charging single gold atoms on oxidized rutile titanium dioxide surface, both positively and negatively, considerably promotes adsorption of carbon monoxide. No carbon monoxide adsorption is observed on neutral gold atoms.

View Article and Find Full Text PDF

Paraffin and octadecyltrichlorosilane (OTS) coatings can alleviate collisions between alkali-metal atoms and cell walls and then prolong the atomic spin-polarization lifetime. The surface structure and collision effects of these antirelaxation coatings, as well as the methods to avoid antirelaxation invalidity, have been the focus of researchers. This study investigated the thermolability of coating surface structure and the collision interactions between alkali metal atoms and coatings, considering the influence of various coating preparation factors, where this collision interaction is indirectly analyzed by measuring the collision energy dissipation between an atomic force microscopy (AFM) probe and the atoms on the coating surface.

View Article and Find Full Text PDF

Gut-microbiome derived short-chain fatty acids exert anti-inflammatory effects and delay progression of kidney disease in diabetic nephropathy. The aim of this study was to examine the impact and of short-chain fatty acid treatment on cellular pathways involved in the development of experimental diabetic nephropathy. To determine the effect of short-chain fatty acids in diabetic nephropathy, we compared wildtype, GPR43-/- and GPR109A-/- mice diabetic mice treated with acetate or butyrate and assessed variables of kidney damage.

View Article and Find Full Text PDF
Article Synopsis
  • A new technique called high-low Kelvin probe force microscopy (KPFM) is introduced to study semiconductor interface states with improved spatial resolution using different AC bias frequencies.
  • The proposed method, high-low Kelvin probe force spectroscopy (KPFS), allows the measurement of interface state density in semiconductors by analyzing electrostatic forces at varying frequencies.
  • Preliminary experiments on ion-implanted silicon showed that the electrostatic force varies with AC bias frequency, enabling the determination of interface state density within the semiconductor bandgap.
View Article and Find Full Text PDF

We propose hybrid phase modulation (PM)/frequency modulation (FM) atomic force microscopy (AFM) to increase the imaging speed of AFM in high-Q environments. We derive the relationship between the phase shift, the frequency shift and the tip-sample interaction force from the equation of motion for the cantilever in high-Q environments. The tip-sample conservative force is approximately given by the sum of the conservative force with respect to the phase shift in the PM mode and that with respect to the frequency shift in the FM mode.

View Article and Find Full Text PDF

The stimulus-responsive room-temperature phosphorescence (RTP) materials have become an increasingly significant topic in the fields of bioimaging, sensing, and anticounterfeiting. However, this kind of materials is scarce to date, especially for the ones with delicate stimulus-responsive behavior. Herein, a universal strategy for multilevel thermal erasure of RTP via chromatographic separation of host-guest doping RTP systems is proposed.

View Article and Find Full Text PDF

Surface photovoltage (SPV) measurements are a crucial way of investigating optoelectronic and photocatalytic semiconductors. The local SPV is generally measured consecutively by Kelvin probe force microscopy (KPFM) in darkness and under illumination, in which thermal drift degrades spatial and energy resolutions. In this study, we propose the method of AC bias Kelvin probe force microscopy (AC-KPFM), which controls the AC bias to nullify the modulated signal.

View Article and Find Full Text PDF

Data from registrational trials of pediatric venous thromboembolism (VTE) treatment are sparse, especially among cancer patients. We conducted a prospective, multicenter, open-label trial (NCT00952380) on dose-finding, safety, and efficacy (measured by 90-day risks of clinically relevant bleeding [CRB] and symptomatic recurrent VTE [srVTE]) of twice-daily subcutaneous dalteparin for acute VTE treatment in patients ≤18 years old. Among 38 patients (cancer, n = 26; noncancer, n = 12), median dalteparin dose requirements per kilogram varied with age but not cancer status.

View Article and Find Full Text PDF

Background: Ceftaroline fosamil has demonstrated superior clinical efficacy versus ceftriaxone for hospitalized adults with moderate-to-severe community-acquired pneumonia (CAP) in a Phase 3 trial in Asia and in a meta-analysis of three trials in Asia, North America, and Europe. Efficacy and safety outcomes for the subset of patients in China in the ASIA CAP trial were analyzed to determine if the same conclusions hold in the China subpopulation.

Methods: Hospitalized adults with Pneumonia Outcomes Research Team risk class III-IV CAP were randomized (1:1) to receive either intravenous ceftaroline fosamil 600 mg every 12 h or ceftriaxone 2 g every 24 h for 5-7 days.

View Article and Find Full Text PDF

Comparative measurements between frequency modulation Kelvin probe force microscopy (FM-KPFM) using low frequency bias voltage and heterodyne FM-KPFM using high frequency bias voltage were performed on the surface potential measurement. A silicon substrate patterned with p- and n-type impurities was used as a quantitative sample. The multi-pass scanning method in the measurements of FM-KPFM and heterodyne FM-KPFM was used to eliminate the effect of the tip-sample distance dependence.

View Article and Find Full Text PDF

Objectives: This exploratory pooled analysis assessed the efficacy and safety of ceftaroline fosamil and comparators across six phase III clinical trials in adults with community-acquired pneumonia (CAP) or complicated skin and soft-tissue infection (cSSTI) and secondary bacteraemia.

Methods: In each trial, FOCUS 1 and 2 (CAP), Asia CAP trial, CANVAS 1 and 2 (cSSTI) and COVERS (cSSTI), patients were randomised to ceftaroline fosamil [600 mg q12h by 1-h i.v.

View Article and Find Full Text PDF

Introduction: In three phase III randomized controlled trials, ceftaroline fosamil was shown to be non-inferior to vancomycin plus aztreonam for the treatment of complicated skin and soft tissue infections (cSSTIs). This exploratory analysis evaluated the impact of underlying comorbidities on clinical outcomes in patients with cSSTI pooled from these three studies.

Methods: CANVAS 1 and 2 and COVERS evaluated ceftaroline fosamil (600 mg every 12 h [q12h]; 600 mg every 8 h [q8h; COVERS]) versus vancomycin plus aztreonam (1 g q12h each [CANVAS 1 and 2]; vancomycin 15 mg/kg q12h and aztreonam 1 g q8h [COVERS]) in hospitalized adults with cSSTI.

View Article and Find Full Text PDF

Titanium dioxide (TiO) is of considerable interest as a photocatalyst and a catalyst support. Surface hydroxyl groups (OH) are the most common adsorbates on the TiO surface and are believed to play crucial roles in their applications. Although the characteristics of bridging hydroxyl (OH) have been well understood, the adsorption structure and charged states of terminal hydroxyl (OH) have not yet been experimentally elucidated at an atomic scale.

View Article and Find Full Text PDF

To investigate the obestatin neural projections from arcuate nucleus (ARC) to hippocampus in diabetic rats, and its effects on gastric motility and gastric emptying of rats. Diabetic model was established by fructose intake combined with streptozotocin injected intraperitoneally in healthy male Wistar rats. Diabetic rats were randomly divided into five groups: control group (NS group), 0.

View Article and Find Full Text PDF

The strain has been employed for controlled modification of electronical and mechanical properties of two-dimensional (2D) materials. However, the thermal strain-engineered behaviors of the CVD-grown MoShave not been systematically explored. Here, we investigated the strain-induced structure and properties of CVD-grown triangular MoSflakes by several advanced atomic force microscopy.

View Article and Find Full Text PDF

Three-dimensional (3D) information of the optical response in the nanometre scale is important in the field of nanophotonics science. Using photoinduced force microscopy (PiFM), we can visualize the nano-scale optical field using the optical gradient force between the tip and sample. Here, we demonstrate 3D photoinduced force field visualization around a quantum dot in the single-nanometre spatial resolution with heterodyne frequency modulation technique, using which, the effect of the photothermal expansion of the tip and sample in the ultra-high vacuum condition can be avoided.

View Article and Find Full Text PDF

Short-chain fatty acids (SCFA) derived from gut microbial fermentation of fiber have been shown to exert anti-inflammatory and immune-modulatory properties in acute kidney injury (AKI). However the direct mechanistic link between SCFAs, diet and the gut microbiome is yet to be established. Using the murine model of folic-acid nephropathy (FAN), we examined the effect of dietary fiber on development of AKI (day 2) and subsequent chronic kidney disease (CKD) (day 28).

View Article and Find Full Text PDF

Background: Solid tumors are a common predisposing factor for invasive candidiasis (IC) or candidemia due to IC.

Objectives: Post hoc analysis of patient-level efficacy and safety data from six studies of anidulafungin (with similar protocols/endpoints) in adults with IC/candidemia summarized by past or recent diagnosis of solid tumors.

Patients/methods: Patients received a single intravenous (IV) dose of anidulafungin 200 mg, followed by 100 mg once daily.

View Article and Find Full Text PDF

The discovery of hydrogen atoms on the TiO surface is crucial for many practical applications, including photocatalytic water splitting. Electronically activating interfacial hydrogen atoms on the TiO surface is a common way to control their reactivity. Modulating the potential landscape is another way, but dedicated studies for such an activation are limited.

View Article and Find Full Text PDF

The atomic arrangement of the Si(110)-(16×2) reconstruction was directly observed using noncontact atomic force microscopy (NC-AFM) at 78 K. The pentagonal structure, which is the most important building block of the reconstruction, was concluded to consist of five atoms, while only four or five spots (depending on tip bias) have been reported with scanning tunneling microscopy (STM). Single atoms were determined to exist near step edges between upper and lower terraces, which have not been reported using STM.

View Article and Find Full Text PDF

Symmetry is highly relevant with various quantities and phenomena in physics. While the translational symmetry breaks at the edges of two-dimensional hexagonal crystalline flakes, it is usually associated with the breaking of central inversion symmetry that is yet to be observed in terms of physical properties. Here, we report an experiment-theory joint study on in-plane compressed single-crystal monolayer WS flakes.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_session7jdrs5s0c33oea4oamud86re15g2pmsl): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once