Redox processes are at the heart of synthetic methods that rely on either electrochemistry or photoredox catalysis, but how do electrochemistry and photoredox catalysis compare? Both approaches ...provide access to high energy intermediates (e.g., radicals) that enable bond formations not constrained by the rules of ionic or 2 electron (e) mechanisms. Instead, they enable 1e mechanisms capable of bypassing electronic or steric limitations and protecting group requirements, thus enabling synthetic chemists to disconnect molecules in new and different ways. However, while providing access to similar intermediates, electrochemistry and photoredox catalysis differ in several physical chemistry principles. Understanding those differences can be key to designing new transformations and forging new bond disconnections. This review aims to highlight these differences and similarities between electrochemistry and photoredox catalysis by comparing their underlying physical chemistry principles and describing their impact on electrochemical and photochemical methods.
Nucleophilic aromatic substitution (SNAr) is a direct method for arene functionalization; however, it can be hampered by low reactivity of arene substrates and their availability. Herein we describe ...a cation radical-accelerated nucleophilic aromatic substitution using methoxy- and benzyloxy-groups as nucleofuges. In particular, lignin-derived aromatics containing guaiacol and veratrole motifs were competent substrates for functionalization. We also demonstrate an example of site-selective substitutive oxygenation with trifluoroethanol to afford the desired trifluoromethylaryl ether.
Highlights • miR-124 expression was downregulated in the SN of the MPTP-induced PD mouse model. • Decreased expression of miR-124 increased the expression of calpain 1. • Calpain 1 activates p25/cdk5 ...expression in miR-124 knockdown MN9D cells. • miR-124 loss in MN9D cells increased ROS and H2 O2 and reduced cell viability. • miR-124 overexpression reduced calpain 1/cdk5 pathway protein expression after MPTP treatment.
A novel nano-adsorbent, carboxymethyl-β-cyclodextrin modified Fe
3O
4 nanoparticles (CMCD-MNPs) is fabricated for removal of copper ions from aqueous solution by grafting CM-β-CD onto the magnetite ...surface via carbodiimide method. The characteristics results of FTIR, TEM, TGA and XPS show that CM-β-CD is grafted onto Fe
3O
4 nanoparticles. The grafted CM-β-CD on the Fe
3O
4 nanoparticles contributes to an enhancement of the adsorption capacity because of the strong abilities of the multiple hydroxyl and carboxyl groups in CM-β-CD to adsorb metal ions. The adsorption of Cu
2+ onto CMCD-MNPs is found to be dependent on pH and temperature. Adsorption equilibrium is achieved in 30
min and the adsorption kinetics of Cu
2+ is found to follow a pseudo-second-order kinetic model. Equilibrium data for Cu
2+ adsorption are fitted well by Langmuir isotherm model. The maximum adsorption capacity for Cu
2+ ions is estimated to be 47.2
mg
/g at 25
°C. Furthermore, thermodynamic parameters reveal the feasibility, spontaneity and exothermic nature of the adsorption process. FTIR and XPS reveal that Cu
2+ adsorption onto CMCD-MNPs mainly involves the oxygen atoms in CM-β-CD to form surface-complexes. In addition, the copper ions can be desorbed from CMCD-MNPs by citric acid solution with 96.2% desorption efficiency and the CMCD-MNPs exhibit good recyclability.
Highlights • Sphk2 expression was down regulated in the SN of MPTP-induced PD mouse model. • Sphk2 loss in MN9D cells led to a reduction in the level of PGC-1α, NRF-1 in vitro. • Loss of Sphk2 ...decreases ATP and increases ROS levels in vitro. • Exogenous S1P increases the expressions of P-CREB, PGC-1α, NRF-1 and ATP in vitro. • S1P functions through the S1P1 receptor.
"Suicidal emperipolesis" is one of the most recently reported processes leading to cell-in-cell structures that promote cell death. This process was discovered in studies investigating the fate of ...autoreactive CD8 T cells activated within the liver. Recently, we reported that activated T cells invaded hepatocytes, formed transient cell-in-cell structures, and were rapidly degraded within endosomal/lysosomal compartments by a non-apoptotic pathway. Importantly, pharmacological inhibition of this process caused intrahepatic accumulation of tissue-reactive T cells and breach of immune tolerance. The characterization of the molecular mechanisms of suicidal emperipolesis is still in its infancy, but initial studies suggest this phenomenon is distinct from other reported cell-in-cell structures. As opposed to the formation of other cell-in-cell structures, suicidal emperipolesis takes place in a non-malignant environment, and without obvious pathology. It is therefore the first cell-in-cell structure described to have a role in maintaining homeostasis in normal physiology in higher organisms. T cell emperipolesis within hepatocytes has also been observed by pathologists in a range of chronic human liver pathologies. As T cell-in-hepatocyte structures resulting from suicidal emperipolesis are very transiently observed in normal physiology, their accumulation during liver disease would suggest that severe tissue injury is promoted by, or associated with, defective T cell clearance. In this review, we compare "suicidal emperipolesis" to other processes leading to cell-in-cell structures, and consider its potential biological roles in maintaining immune homeostasis and tolerance in the context of the hepatic environment.
Abstract
Background
frail patients in any age group are more likely to die than those that are not frail. We aimed to evaluate the impact of frailty on clinical mortality, readmission rate and length ...of stay for emergency surgical patients of all ages.
Methods
a multi-centre prospective cohort study was conducted on adult admissions to acute surgical units. Every patient presenting as a surgical emergency to secondary care, regardless of whether they ultimately underwent a surgical procedure was included. The study was carried out during 2015 and 2016.
Frailty was defined using the 7-point Clinical Frailty Scale. The primary outcome was mortality at Day 90. Secondary outcomes included: mortality at Day 30, length of stay and readmission within a Day 30 period.
Results
the cohort included 2,279 patients (median age 54 years IQR 36–72; 56% female). Frailty was documented in patients of all ages: 1% in the under 40’s to 45% of those aged 80+. We found that each incremental step of worsening frailty was associated with an 80% increase in mortality at Day 90 (OR 1.80, 95% CI: 1.61–2.01) supporting a linear dose–response relationship. In addition, the most frail patients were increasingly likely to stay in hospital longer, be readmitted within 30 days, and die within 30 days.
Conclusions
worsening frailty at any age is associated with significantly poorer patient outcomes, including mortality in unselected acute surgical admissions. Assessment of frailty should be integrated into emergency surgical practice to allow prognostication and implementation of strategies to improve outcomes.
Aims: The effect of high organic loading rate (OLR) on the physical characteristics of aerobic granules was studied.
Methods and Results: Two column‐type sequential aerobic sludge blanket reactors ...were fed with either glucose or acetate as the main carbon source, and the OLR was gradually raised from 6 to 9, 12 and 15 kg chemical oxygen demand (COD) m−3 d−1. Glucose‐fed granules could sustain the maximum OLR tested. At a low OLR, these granules exhibited a loose fluffy morphology dominated by filamentous bacteria. At higher OLRs, these granules became irregularly shaped, with folds, crevices and depressions. In contrast, acetate‐fed granules had a compact spherical morphology at OLRs of 6 and 9 kg COD m−3 d−1, with better settling and strength characteristics than glucose‐fed granules at similar OLRs. However, acetate‐fed granules could not sustain high OLRs and disintegrated when the OLR reached 9 kg COD m−3 d−1.
Conclusions: The compact regular microstructure of the acetate‐fed granules appeared to limit mass transfer of nutrients at an OLR of 9 kg COD m−3 d−1. The looser filamentous microstructure of the glucose‐fed granules and the subsequent irregular morphology delayed the onset of diffusion limitation and allowed significantly higher OLRs to be attained.
Significance and Impact of the Study: High organic loading rates are possible with aerobic granules. This research would be helpful in the development of aerobic granule‐based systems for high‐strength wastewaters.
•Starch based biopolymer films have poor mechanical and barrier properties.•Lignin, a natural biopolymer was extracted from oil palm black liquor waste.•Novel, food packaging films were produced by ...utilizing sago starch/lignin.•Packaging films showed improved thermo-mechanical and barrier properties.•This packaging film will be more economical and environmental friendly.
Poor mechanical and barrier properties of starch-based films can be improved by incorporating natural polymer such as lignin. In the present study, novel food packaging films were prepared by casting method from sago palm (Metroxylon sagu) starch (as film matrix with 30% w/w glycerol as plasticizer) by adding lignin isolated from oil palm black liquor waste (from empty fruit bunch), as a reinforcing material (1, 2, 3, 4 and 5% v/w). Results showed packaging films produced by incorporation of isolated lignin to improve selected thermo-mechanical and barrier properties with significant reduction in water vapor permeability, and improved water resistance and seal strength. It is concluded that lignin isolated from oil palm black liquor waste to have great potential to be explored for food packaging purposes. Moreover, this packaging film will be more economical and environmental friendly.
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