8 research outputs found
Design criteria and applications of multi-channel parallel microfluidic module
The microfluidic technology for function microsphere synthesis has high control precision. However, the throughput is too low for industrial scale-up applications. Current scale-up design focuses on a multi-channel in 2D, in which the distribution uniformity parameter δ increases linearly, resulting in the deterioration of the flow distribution performance. The 3D modular scale-up strategy could greatly alleviate this problem, but no design principles have been developed yet. For the first time, this paper establishes the microfluidic 3D scale-up design criteria. Based on the modular design concept, the design method of 2D and 3D throughput scale-up parameters N and M, distribution uniformity parameters δ and β, and microchannel design parameter KRwere proposed. The equivalent resistance coefficient was defined, and the influence of different parameters on a 2D array and 3D stack was analyzed. Furthermore, the error correction method was studied. It was found that the two-stage scale-up process contradicted each other. A good scale-up performance of one stage led to the limitation of another stage. Increasing the resistance of each channel Rucould both increase the two-stage scale-up performance, which was an important factor. A single-module scale-up system with 8 channels in a single array and 10 arrays in a vertical stack, which had 80 channels in total, was designed and fabricated based on the proposed design criteria for generating Chitosan/TiO2composite microspheres. The average particle size was 539.65 μm and CV value was about 3.59%. The throughput was 480 ml h-1, which effectively increased the throughput scale and the product quality
Iron Hydroxide-Modified Nickel Hydroxylphosphate Single-Wall Nanotubes as Efficient Electrocatalysts for Oxygen Evolution Reactions
Development of efficient
electrocatalysts for oxygen evolution
reaction (OER) is of great significance for future renewable energy
applications. Herein, efficient OER electrocatalysts based on iron
hydroxide-modified nickel hydroxylphosphate (NiPO/FeÂ(OH)<sub><i>x</i></sub>) single-wall nanotubes (SWNTs) have been prepared
by a facile stepwise surfactant-free solvothermal strategy, which
possess diameters of about 6 nm and lengths of about several micrometers.
Benefiting from the synergistic effect between iron hydroxides and
NiPO SWNTs, the as-prepared NiPO/FeÂ(OH)<sub><i>x</i></sub> SWNTs exhibit higher OER activity than primary NiPO SWNTs. Furthermore,
the OER activity with different Fe contents displays a volcano-type
shape, and the optimized NiPO/FeÂ(OH)<sub><i>x</i></sub> SWNTs
present excellent activity with a low overpotential of 248 mV to deliver
a current density of 10 mA cm<sup>–2</sup> and 323 mV to achieve
a large current density of 100 mA cm<sup>–2</sup>, as well
as a remarkably low Tafel slope of 45.4 mV dec<sup>–1</sup> in 1 M KOH electrolyte. The present work provides valuable insights
to improve the OER performance by rational surface modification
Step-by-Step Strategy from Achiral Precursors to Polyoxometalates-Based Chiral Organic–Inorganic Hybrids
Using
two types of triol ligands, several novel asymmetrically triol-functionalized
Anderson organic hybrids have been efficiently synthesized in high
purity and good yields via a convenient two-step esterification reaction.
These organic–inorganic hybrids are chiral and can be spontaneously
resolved with suitable solvents. Their molecular and crystal structures
have been confirmed by single-crystal X-ray diffraction studies. Stable
solid-state chirality of the corresponding enantiopure crystals has
also been confirmed definitively by CD spectra. Interestingly, these
organic–inorganic hybrids possess a layer-by-layer structure,
forming solvent-accessible nanoscale chiral channels via a 1D infinite
helical chain substructure. TGA measurements indicated that the species
of the central heteroatoms significantly effects the stability of
these compounds
A Series of Weakley-type Polyoxomolybdates: Synthesis, Characterization, and Magnetic Properties by a Combined Experimental and Theoretical Approach
Using DCC as the
dehydrating agent, a series of Weakley-type polyoxomolybdates [Bu<sub>4</sub>N]<sub>3</sub>{LnÂ[Mo<sub>5</sub>O<sub>13</sub>(OMe)<sub>4</sub>(NO)]<sub>2</sub>} (Ln = Tb, Dy, Ho, Er) were synthesized in a one-pot
reaction and structurally characterized by elemental, IR, UV–vis
analysis, PXRD, and single-crystal X-ray diffraction. Furthermore,
the static and dynamic measurements were utilized to investigate their
magnetic performances. Typically, slow relaxation of magnetization
was observed for Dy analogues with an energy barrier for the reversal
of the magnetization of 50 K, which is the highest barrier height
observed on the polyoxomolybdates-based single-molecule magnets (SMMs).
For a deep understanding of the appearance of the SMM behavior on
Weakley-type polyoxomolybdates series, <i>ab initio</i> calculations
on {DyÂ[Mo<sub>5</sub>O<sub>13</sub>(OMe)<sub>4</sub>(NO)]<sub>2</sub>}<sup>3–</sup> have been conducted
Quasi-Racemic X‑ray Structures of K27-Linked Ubiquitin Chains Prepared by Total Chemical Synthesis
Quasi-racemic
crystallography has been used to determine the X-ray
structures of K27-linked ubiquitin (Ub) chains prepared through total
chemical synthesis. Crystal structures of K27-linked di- and tri-ubiquitins
reveal that the isopeptide linkages are confined in a unique buried
conformation, which provides the molecular basis for the distinctive
function of K27 linkage compared to the other seven Ub chains. K27-linked
di- and triUb were found to adopt different structural conformations
in the crystals, one being symmetric whereas the other triangular.
Furthermore, bioactivity experiments showed that the ovarian tumor
family de-ubiquitinase 2 significantly favors K27-linked triUb than
K27-linked diUb. K27-linked triUb represents the so-far largest chemically
synthesized protein (228 amino acids) that has been crystallized to
afford a high-resolution X-ray structure
PFASs in Cerebrospinal Fluids and Blood–CSF Barrier Permeability in Patients with Cognitive Impairment
Attention
has been drawn to the associations between PFASs and
human cognitive decline. However, knowledge on the occurrence and
permeability of PFASs in the brains of patients with cognitive impairment
has not been reported. Here, we determined 30 PFASs in paired sera
and cerebrospinal fluids (CSFs) from patients with cognitive impairment
(n = 41) and controls without cognitive decline (n = 18). We revealed similar serum PFAS levels but different
CSF PFAS levels, with lower CSF PFOA (median: 0.125 vs 0.303 ng/mL, p p < 0.05) in patients than in controls. Blood–brain
transfer rates also showed lower RCSF/Serum values for PFOA and higher RCSF/Serum values for PFOS in patients, implying potential heterogeneous associations
with cognitive function. The RCSF/Serum values for C4–C14 perfluoroalkyl carboxylates exhibited a U-shape trend with increasing chain length. Logistic regression
analyses demonstrated that CSF PFOS levels were linked to the heightened
risk of cognitive impairment [odds ratio: 3.22 (1.18–11.8)]
but not for serum PFOS. Toxicity inference results based on the Comparative
Toxicogenomics Database suggested that PFOS in CSF may have a greater
potential to impair human cognition than other PFASs. Our results
contribute to a better understanding of brain PFAS exposure and its
potential impact on cognitive function
Monomer/Oligomer Quasi-Racemic Protein Crystallography
Racemic or quasi-racemic
crystallography recently emerges as a
useful technology for solution of the crystal structures of biomacromolecules.
It remains unclear to what extent the biomacromolecules of opposite
handedness can differ from each other in racemic or quasi-racemic
crystallography. Here we report a finding that monomeric d-ubiquitin (Ub) has propensity to cocrystallize with different dimers,
trimers, and even a tetramer of l-Ub. In these cocrystals
the unconnected monomeric d-Ubs can self-assemble to form
pseudomirror images of different oligomers of l-Ub. This
monomer/oligomer cocrystallization phenomenon expands the concept
of racemic crystallography. Using the monomer/oligomer cocrystallization
technology we obtained, for the first time the X-ray structures of
linear M1-linked tri- and tetra-Ubs and a K11/K63-branched tri-Ub
Additional file 1 of Liver biomarkers, lipid metabolites, and risk of gestational diabetes mellitus in a prospective study among Chinese pregnant women
Additional file 1: Table S1. Associations of liver biomarkers with blood glucose values in OGTT. Table S2. Joint associations of higher liver enzymes with risk of GDM. Table S3. Association of HSI with risk of GDM stratified by pre-pregnancy BMI and alcohol drinking status. Table S4. Associations of liver biomarkers with GDM after excluding participants with a history of GDM, current smokers, or current drinkers. Table S5. Associations of liver biomarkers with GDM among participants within relatively normal range of liver biomarkers. Table S6. Associations of liver biomarkers with GDM after multiple imputation. Table S7. Associations of liver biomarkers with GDM in Poisson regression. Table S8. Associations of liver biomarkers with GDM in a subset of 921 participants. Table S9. Association of HSI-related lipid score with GDM in a subset of 948 participants. Figure S1. Flowchart of the participant selection. Figure S2. Restricted cubic spline analyses for the associations of liver biomarkers with GDM risk. Figure S3. Spearman partial correlations between liver biomarkers and metabolic profiles