Generating ultrafast pulses with better spectrotemporal control is crucial for optimizing and characterizing nonlinear light–matter responses, yet it is limited by the gain bandwidth of laser media ...or the phase‐matching geometry of nonlinear processes. This work proposes a simple approach to independently manage a femtosecond source's spectral location and bandwidth. Self‐phase‐modulation‐enabled spectral broadening is first analyzed, which is potentially energy‐scalable using hollow‐core capillaries or multipass cells. It is demonstrated that the outmost lobes in the broadened spectrum show different dependencies on the initial pulse energy and duration. A simple yet effective toy model is introduced that successfully predicts broadband spectral tuning, and the impact of other nonlinear effects, dispersion, and input pulse asymmetry on the experimental scenario is also discussed. Thus a fiber‐based versatile source is demonstrated, which is compressible down to its transform‐limit duration, as short as 12.2 fs centered at 920 nm. In addition, bandwidth‐dependent third‐harmonic generation spectroscopy is performed from a dielectric metasurface with an optimized nonlinear response, and the dependency of laser bandwidth and pulse duration is investigated on the signal‐to‐background ratio of two‐photon images. It is believed that this demonstration will advance the investigation of bandwidth‐dependent nonlinear spectroscopy and microscopy.
Independent control of femtosecond sources’ spectral location and bandwidth is realized with a simple approach enabled by self‐phase modulation. This work thus demonstrates a fiber‐based versatile source, delivering pulses compressible down to few‐optical‐cycle regimes. These demonstrations pave the way for deeper insights into the spectral response of nonlinear resonances, further advancing the field of bandwidth‐dependent nonlinear spectroscopy and microscopy.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Two novel mixed-ligand coordination polymers, {Co(tdc)(btrp)·0.67DMF}
(1) and
{Zn
(bimb)
(tdc)
·2H
O}
(2) involving 2,5-thiophenedicarboxylate (H
tdc), and bitopic
flexible N-donor ligands, ...1,3-bis(1,2,4-triazol-1-yl)propane (btrp) and
1,4-bis((1
-benzo
imidazol-1-yl)methyl)benzene
(bimb), have been synthesized by the hydrothermal method and characterized via IR,
elemental analysis, thermal analysis, and powder X-ray diffraction. The biological
functional studies were performed; the treatment activity of the compounds on
periodontitis and the specific mechanism was explored. First, the real-time RT-PCR
was carried out to determine the inflammatory genes
and
relative expression in periodontal mucosal cells after
treating with compounds
and
. Then, the level of the
inflammatory cytokine in the gingival crevicular fluid after treating with compounds
was also determined by the ELISA detection kit.
Formaldehyde is a reactive carbonyl species (RCS) that is produced naturally in the human body via metabolic and epigenetic biochemical processes, yet in high concentrations is highly toxic to the ...environment as well as to living organisms. Therefore, we designed two ratiometric electrochemical molecular redox probes, Formaldehyde oxidative latent probe (FOLP) and dihydroxy-formaldehyde oxidative latent probe (HFOLP), for the selective profiling of endogenous formaldehyde. FOLP and HFOLP each underwent the aza-Cope reaction with formaldehyde followed by hydrolysis to eliminate unmask redox reporter N-alkylated aminoferrocene (AAF) to monitor their response current. The FOLP and HFOLP sensors showed broad dynamic ranges of 0.12–1000 μM and 0.09–3 mM for formaldehyde with detection limits of 48.2 nM and 31.6 μM, respectively. Also, since formaldehyde is the byproduct of biochemical reactions for detecting creatinine and creatinine is an important biomarker for chronic kidney disease (CKD), we tested the FOLP probe for its ability to monitor creatinine. It successfully did so, and this ability was used to develop an electrochemical platform for the quantification of creatinine; it showed a dynamic range of 3.25–200 μM and a limit of detection (1.3 μM). In addition, the FOLP-based assay platform delivered a reliable analytical performance for the quantification of formaldehyde in human whole blood and of creatinine in saliva, and also for the real-time monitoring of endogenous formaldehyde secretion in HeLa cells. Moreover, the concentrations determined using our method were found to be consistent with those determined using formaldehyde and creatinine fluorometric assay kits.
•FOLP based formaldehyde sensor: proof-of-concept via cyclic voltammetry and differential pulse voltammetry, linear range = 0.12–1000 μM, detection limit = 48.2 nM.•FOLP based enzymatic creatinine assay: proof-of-concept via differential pulse voltammetry, linear range = 3.25–200 μM, detection limit = 1.3 μM.•Highly selective for formaldehyde over other RCS, enzymes, amino acids, and bio species.•Real sample analysis of formaldehyde in whole blood samples and creatinine in saliva.•In real-time, quantification of endogenous formaldehyde production in HeLa cells.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
By precisely managing fiber-optic nonlinearity with anomalous dispersion, we have demonstrated the control of generating plural few-optical-cycle pulses based on a 24-MHz Chromium:forsterite laser, ...allowing multicolor two-photon tissue imaging by wavelength mixing. The formation of high-order soliton and its efficient coupling to dispersive wave generation leads to phase-matched spectral broadening, and we have obtained a broadband continuum ranging from 830 nm to 1200 nm, delivering 5-nJ pulses with a pulse width of 10.5 fs using a piece of large-mode-area fiber. We locate the spectral enhancement at around 920 nm for the two-photon excitation of green fluorophores, and we can easily compress the resulting pulse close to its limited duration without the need for active pulse shaping. To optimize the wavelength mixing for sum-frequency excitation, we have realized the management of the power ratio and group delay between the soliton and dispersive wave by varying the initial pulse energy without additional delay control. We have thus demonstrated simultaneous three-color two-photon tissue imaging with contrast management between different signals. Our source optimization leads to efficient two-photon excitation reaching a 500-µm imaging depth under a low 14-mW illumination power. We believe our source development leads to an efficient and compact approach for driving multicolor two-photon fluorescence microscopy and other ultrafast investigations, such as strong-field-driven applications.
Sub-terahertz (Sub-THz) waves possess exceptional attributes, capable of penetrating non-metallic and non-polarized materials while ensuring bio-safety. However, their practicality in imaging is ...marred by the emergence of troublesome speckle artifacts, primarily due to diffraction effects caused by wavelengths comparable to object dimensions. In addressing this limitation, we present the Diffuser-aided sub-THz Imaging System (DaISy), which utilizes a diffuser and a focusing lens to convert coherent waves into incoherent counterparts. The cornerstone of our progress lies in a coherence theory-based theoretical framework, pivotal for designing and validating the THz diffuser, and systematically evaluating speckle phenomena. Our experimental results utilizing DaISy reveal substantial improvements in imaging quality and nearly diffraction-limited spatial resolution. Moreover, we demonstrate a tangible application of DaISy in the scenario of security scanning, highlighting the versatile potential of sub-THz waves in miscellaneous fields.
Sub-terahertz (Sub-THz) waves possess exceptional attributes, capable of penetrating non-metallic and non-polarized materials while ensuring bio-safety. However, their practicality in imaging is ...marred by the emergence of troublesome speckle artifacts, primarily due to diffraction effects caused by wavelengths comparable to object dimensions. In addressing this limitation, we present the Diffuser-aided sub-THz Imaging System (DaISy), which utilizes a diffuser and a focusing lens to convert coherent waves into incoherent counterparts. The cornerstone of our progress lies in a coherence theory-based theoretical framework, pivotal for designing and validating the THz diffuser, and systematically evaluating speckle phenomena. Our experimental results utilizing DaISy reveal substantial improvements in imaging quality and nearly diffraction-limited spatial resolution. Moreover, we demonstrate a tangible application of DaISy in the scenario of security scanning, highlighting the versatile potential of sub-THz waves in miscellaneous fields.
Deoxyshikonin (DSK) is a biological component derived from Lithospermum erythrorhizon. Although DSK possesses potential anticancer activities, whether DSK exerts anticancer effects on cervical cancer ...cells is incompletely explored. This study was aimed to investigate the anticancer activity of DSK against cervical cancer cells and its molecular mechanisms. Cell viability was evaluated by MTT assay. Level of phosphorylation and protein was determined using Western blot. Involvement of signaling kinases was assessed by specific inhibitors. Our results revealed that DSK reduced viability of human cervical cell in a dose‐dependent fashion. Meanwhile, DSK significantly elicited apoptosis of HeLa and SiHa cells. Apoptosis microarray was used to elucidate the involved pathways, and the results showed that DSK dose‐dependently diminished cellular inhibitor of apoptosis protein 1 (cIAP1), cIAP2, and XIAP, and induced cleavage of poly(ADP‐ribose) polymerase (PARP) and caspase‐8/9/3. Furthermore, we observed that DSK significantly triggered activation of ERK, JNK, and p38 MAPK (p38), and only inhibition of p38 diminished the DSK‐mediated pro‐caspases cleavage. Taken together, our results demonstrate that DSK has anti‐cervical cancer effects via the apoptotic cascade elicited by downregulation of IAPs and p38‐mediated caspase activation. This suggests that DSK could act as an adjuvant to facilitate cervical cancer management.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The one month survival rate after out-of-hospital cardiac arrest (OHCA) in the paediatric population remains low. Improving survival in paediatric OHCA by enhancing the quality of cardiopulmonary ...resuscitation (CPR) is important. In this study, we aimed to analyse the factors associated with CPR quality by using a real-time feedback device. Participants were prospectively divided into 4 groups: paediatric research fellows, paediatric residents, medical students (clerks), and paediatric critical care nurses. Then, the participants were asked to perform 5 cycles of CPR on a paediatric simulation manikin without prompts from feedback devices, and to repeat another 5 cycles of CPR after education with the 2015 paediatric advanced life support guidelines. A total of 75 participants were evaluated. In the overall analysis, an improvement in the percentage of participants meeting the target compression rate was observed (from 49.82% to 71.23%, P < 0.001). The percentage of participants achieving the target compression depth improved from 73.77% to 85.63% (P = 0.005). Among the 4 groups, the residents showed the most significant improvement in both compression rate (from 48.41% to 86.57%, P < 0.001) and compression depth (from 63.50% to 95.57%, P < 0.001). Inappropriate rate was a more important factor resulting in inadequate CPR performance than inappropriate depth. An excessive compression rate was also a common problem. In conclusions, the real-time CPR feedback device may help clinical physicians and nurses in improving the quality of chest compression. Excessive CPR compression rate may be a major cause of inadequate CPR performance.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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