106 research outputs found
Specific two-photon imaging of live cellular and deep-tissue lipid droplets by lipophilic AIEgens at ultra-low concentration
Lipid droplets are highly associated with obesity, diabetes, inflammatory disorders and cancer. A reliable two-photon dye for specific lipid droplets imaging in live cells and live tissues at ultra-low concentration has rarely been reported. In this work, four new aggregation-induced emission luminogens (AIEgens) based on the naphthalene core
were designed and synthesized for specific two-photon lipid droplets staining. The new molecules, namely NAP AIEgens, exhibit large Stokes shift (>110 nm), high solid-state fluorescence quantum yield (up to 30%), good two-photon absorption cross section (45–100 GM at 860 nm), high biocompatibility and good photostability. They could specifically stain lipid droplets at ultra-low concentration (50 nM) in a short time of 15 min. Such ultra-low concentration is the lowest value for lipid droplets staining in live cells reported so far. In vitro and ex vivo two-photon imaging of lipid droplets in live cells and live mice liver tissues were successfully demonstrated. In addition, selective visualization of lipid droplets in live mice liver tissues could be achieved at a depth of about 70 μm. These excellent properties render them as promising candidates for investigating lipid droplets-associated physiological and pathological processes in live biological samples
Regeneration of NAD(P)H and its Analogues by Photocatalysis with Ionized Carbon Nitride
The regeneration of NAD(P)H and its analogues is crucial
for biocatalytic
processes. However, despite the efficiency of enzymatic catalysis
in regenerating NAD(P)H, the sustainability of enzymes is often compromised,
particularly under extreme catalytic conditions. Moreover, artificial
cofactors may present advantages in certain reactions due to their
stability and versatility, yet the substrate specificity of enzymes
poses significant challenges to their regeneration through the enzymatic
method. Therefore, it is imperative to develop a highly stable regeneration
method that can be adapted to both natural and artificial cofactors.
In this work, employing potassium-ion-doped carbon nitride (ionCN-0.2)
as a catalyst not only achieves high-efficiency photocatalytic regeneration
of NAD(P)H, comparable to that of glucose dehydrogenase (GDH), but
also a remarkable ability to regenerate nicotinamide analogues. This
enhanced performance stems from the tunable negative ζ-potential,
which effectively adsorbs the positively charged [Cp*Rh(bpy)H2O]2+ mediator, resulting in enhanced regeneration
kinetics of the nicotinamide moiety. The catalyst demonstrates superior
performance compared to the reported systems; the optimal regeneration
rate reaches 0.55 mmol L–1 gcat–1 min–1 and approaches enzymatic regeneration efficiency.
Expanding the reaction conditions to a wider temperature and pH range
also confirms the effectiveness and sufficient stability of this photocatalytic
system, offering a promising strategy for stable cofactor regeneration
in biocatalytic processes
Image1_A novel necroptosis-related lncRNA signature predicts the prognosis and immune microenvironment of hepatocellular carcinoma.TIF
Hepatocellular carcinoma (HCC) is one of the malignant tumors with high mortality and a worse prognosis globally. Necroptosis is a programmed death mediated by receptor-interacting Protein 1 (RIP1), receptor-interacting Protein 1 (RIP3), and Mixed Lineage Kinase Domain-Like (MLKL). Our study aimed to create a new Necroptosis-related lncRNAs (NRlncRNAs) risk model that can predict survival and tumor immunity in HCC patients. The RNA expression and clinical data originated from the TCGA database. Pearson correlation analysis was applied to identify the NRlncRNAs. The LASSO-Cox regression analysis was employed to build the risk model. Next, the ROC curve and the area under the Kaplan-Meier curve were utilized to evaluate the accuracy of the risk model. In addition, based on the two groups of risk model, we performed the following analysis: clinical correlation, differential expression, PCA, TMB, GSEA analysis, immune cells infiltration, and clinical drug prediction analysis. Plus, qRT-PCR was applied to test the expression of genes in the risk model. Finally, a prognosis model covering six necroptosis-related lncRNAs was constructed to predict the survival of HCC patients. The ROC curve results showed that the risk model possesses better accuracy. The 1, 3, and 5-years AUC values were 0.746, 0.712, and 0.670, respectively. Of course, we also observed that significant differences exist in the following analysis, such as functional signaling pathways, immunological state, mutation profiles, and medication sensitivity between high-risk and low-risk groups of HCC patients. The result of qRT-PCR confirmed that three NRlncRNAs were more highly expressed in HCC cell lines than in the normal cell line. In conclusion, based on the bioinformatics analysis, we constructed an NRlncRNAs associated risk model, which predicts the prognosis of HCC patients. Although our study has some limitations, it may greatly contribute to the treatment of HCC and medical progression.</p
Reactions of CO, H<sub>2</sub>O, CO<sub>2</sub>, and H<sub>2</sub> on the Clean and Precovered Fe(110) Surfaces – A DFT Investigation
The reactions of CO and H<sub>2</sub>O on the clean Fe(110) surface
as well as surfaces with 0.25 monolayer O, OH, and H precoverage have
been computed on the basis of density functional theory (GGA-PBE).
Under the considerations of the reductive nature of CO as reactant
and H<sub>2</sub> as product as well as the oxidative nature of CO<sub>2</sub> and H<sub>2</sub>O, we have studied the potential activity
of metallic iron in the water-gas shift reaction. On the clean surface,
CO oxidation following the redox mechanism has a similar barrier as
CO dissociation; however, CO dissociation is much more favorable thermodynamically.
Furthermore, surfaces with 0.25 monolayer O, OH, and H precoverage
promote CO hydrogenation, while they suppress CO oxidation and dissociation.
On the surfaces with different CO and H<sub>2</sub>O ratios, CO hydrogenation
is promoted. On all of these surfaces, COOH formation is not favorable.
Considering the reverse reaction, CO<sub>2</sub> dissociation is much
favorable kinetically and thermodynamically on all of these surfaces,
and CO<sub>2</sub> hydrogenation should be favorable. Finally, metallic
iron is not an appropriate catalyst for the water-gas shift reaction
Mechanisms of H<sub>2</sub>O and CO<sub>2</sub> Formation from Surface Oxygen Reduction on Co(0001)
Surface
O removal by H and CO on Co(0001) has been studied using
periodic density functional method (revised Perdew–Burke–Ernzerhof
; RPBE) and ab initio atomistic thermodynamics. On the basis of the
quantitative agreement in the H<sub>2</sub>O formation barrier between
experiment (1.34 ± 0.07 eV) and theory (1.32 eV), H<sub>2</sub>O formation undergoes a consecutive hydrogenation process [O + 2H
→ OH + H → H<sub>2</sub>O], while the barrier of H<sub>2</sub>O formation from OH disproportionation [2OH → H<sub>2</sub>O + O] is much lower (0.72 eV). The computed desorption temperatures
of H<sub>2</sub> and H<sub>2</sub>O under ultrahigh vacuum conditions
agree perfectly with the experiment. Surface O removal by CO has a
high barrier (1.41 eV) and is strongly endothermic (0.94 eV). Precovered
O and OH species do not significantly affect the barriers of H<sub>2</sub>O and CO<sub>2</sub> formation. All of these results indicate
that the present RPBE method and the larger surface model are more
suitable for studying cobalt systems
Dissociative Hydrogen Adsorption on the Hexagonal Mo<sub>2</sub>C Phase at High Coverage
Hydrogen
adsorption on the primarily exposed (001), (100), (101), and (201)
surfaces of the hexagonal Mo<sub>2</sub>C phase at different coverage
has been investigated at the level of density functional theory and
using ab initio thermodynamics. On the Mo-terminated (001) and (100)
as well as mixed Mo/C-terminated (101) and (201) surfaces, dissociative
H<sub>2</sub> adsorption is favored both kinetically and thermodynamically.
At high coverage, each surface can have several types of adsorption
configurations coexisting, and these types are different from surface
to surface. The stable coverage as a function of temperature and partial
pressure provides useful information not only for surface science
studies at ultrahigh vacuum condition but also for practical applications
at high temperature and pressure in monitoring reactions. The differences
in the adsorbed H atom numbers and energies of these surfaces indicate
their different potential hydrotreating abilities. The relationship
between surface stability and stable hydrogen coverage has been discussed
Adsorption Equilibria of CO Coverage on β-Mo<sub>2</sub>C Surfaces
Adsorption and surface coverage of CO on the (001), (101),
and
(201) surfaces of β-Mo<sub>2</sub>C were computed at the level
of density functional theory under the consideration of the temperature
and CO partial pressure by using the ab initio atomistic thermodynamic
method. On the basis of the computed Gibbs free energies, the relationship
between CO coverage on the surfaces and temperature as well as CO
partial pressure has been established, and excellent agreements have
been found between the predicated CO desorption temperatures and the
experimentally recorded temperature programmed desorption (TPD) spectra.
These computed phase diagrams show that a stable CO coverage can be
obtained within a range of temperature and partial pressure; different
surfaces can have different coverage at the same conditions, and different
partial pressure has a different desorption temperature. In addition,
these phase diagrams provide useful information for adjusting the
balance between temperature and CO partial pressure for a stable CO
coverage and for identifying the active surface and the initial states
under given conditions. These results should also be very interesting
for surface science under ultra high vacuum conditions
Expression of miRNA precursor and its major mature form in 15 mouse tissues.
<p>A heat map was constructed using GenePattern software based on the normalized miRNA reads. Heat maps showed precursors and major forms to have similar patterns of expression.</p
Single Gold Atom Adsorption on the Fe<sub>3</sub>O<sub>4</sub>(111) Surface
For understanding the catalytic activity of Fe<sub>3</sub>O<sub>4</sub>-supported gold catalysts, the adsorption structures
and energies
of a single Au atom on the six terminations of the Fe<sub>3</sub>O<sub>4</sub>(111) surface have been computed at the level of density functional
theory (GGA+<i>U</i>). For the most stable adsorption configurations,
correlation has been found between the surface stability and the Au
atom adsorption energy; that is, the more stable the surface, the
lower the Au atom adsorption energy. It is also found that the adsorbed
Au atom is reduced and has a negative charge on the iron-terminated
surfaces, whereas it is oxidized and has a positive charge on the
oxygen-terminated surfaces, and the latter is in agreement with the
experimental observation. No correlation between the transferred charge
and the adsorption energy has been found. Regarding the experimentally
observed oxidation of gold nanoparticles on the iron oxide surface,
it is possible to produce an oxygen-terminated surface for gold adsorption
by synthetic tuning
Efficient electrocatalytic alkyne Semi-Hydrogenation and deuteration using Pd/PANI catalysts supported on nickel foam
In this study, we synthesized Pd/PANI catalysts anchored on nickel foam (NF) via a single-step CV electrodeposition process. The resulting Pd0.3/PANI-NF materials exhibited outstanding selectivity and activity for electrocatalytic alkyne semi-hydrogenation and deuteration under ambient conditions. Characterization of Pd/PANI and control experiment revealed that the combination of PANI and Pd had a synergistic effect on the catalytic performance of Pd/PANI-NF for alkyne semi-hydrogenation. Optimized conditions in H-cells allowed efficient conversion of various terminal and internal alkynes into their corresponding alkenes with remarkable yields up to 92 % and a Faradaic efficiency of 88 %, even at low Pd loading (0.4 mol%). The Pd0.3/PANI-NF showed sustained catalytic activity for gram-scale alkene synthesis through five usage cycles under continuous flow conditions, marked by a high TOF (up to 230 h−1) and combined TONs of 2151, establishing its practical viability for electrocatalytic hydrogenation
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