Regulable pyrrolic-N-doped carbon materials as an efficient electrocatalyst for selective O2 reduction to H2O2

Metal-free nitrogen-doped carbon catalysts with pyrrolic-N as the active site were efficiently synthesized via a direct carbonization method, which exibited a high two-electron oxygen reduction reaction performance.

A study of the potential effect of yellow mealworm (Tenebrio molitor) substitution for fish meal on growth, immune and antioxidant capacity in juvenile largemouth bass (Micropterus salmoides)

This study aimed to evaluate the effects of partial replacement of fish meal (FM) with yellow mealworm (Tenebrio molitor, TM) on the growth performance, food utilization and intestinal immune response of juvenile largemouth bass (Micropterus salmoides). Seven diets containing increasing levels of TM (FM substitution) were designed (approximately 0% (0%), 4% (11.1%), 8.1% (22.2%), 12.2% (33.3%), 16.3% (44.4%), 20.4% (55.5%), and 24.5% (66.6%), designated TM0, TM11, TM22, TM33, TM44, TM55, and TM66, respectively). 420 fish were randomly selected and placed in 21 cages (1 m*1 m*1 m, 7 treatments for triplicate, 20 fish per cage). Fish (initial weight 6.25 ± 0.03 g) were fed seven isonitrogenous (47%) and isocaloric (19 MJ kg^-1) diets to satiety twice daily for 8 weeks. Compared to the control group (TM0), TM11 showed no significant difference in the weight gain rate (WGR), specific growth rate (SGR) or feed conversion ratio (FCR), while all other TM inclusion groups presented different degrees of decline. There was no significant difference in the whole-body composition among all groups (P > 0.05). Plasma total protein (TP), triglyceride (TG) and albumin (ALB) contents were significantly decreased in TM55 and TM66 (P < 0.05). The highest plasma aspartate transaminase (AST) activity was observed in TM66 (P < 0.05). TM33, TM44 and TM55 showed the lowest activities of plasma alanine amiotransferase (ALT) and alkaline phosphatase (ALP) (P < 0.05). Moreover, increased mRNA levels of superoxide dismutase (SOD) and catalase (CAT) were measured in the TM11 to TM55 groups, while intestinal SOD activity peaked in TM11 (P < 0.05). With the exception of TM11, the other TM inclusion groups showed significant inhibition of the relative expression of RelA, C3 and TNF-α (P < 0.05). All experimental groups exhibited lower expression of IL-10 than TM0 (P < 0.05). The TM11 group showed significantly upregulated expression of IL-1β and TGF-β (P < 0.05). In addition, TLR2 expression was increased in TM11 and TM22 (P < 0.05). Considering enzyme activities and immune-related gene expression, TM supplementation levels should not exceed 4% (TM11).

Radical spirocyclization of biaryl ynones for the construction of NO2-containing spiro[5.5]trienones

An efficient 6-exo-trig radical cascade reaction of biaryl ynones with NaNO2 was developed to afford nitro-functionalized spiro[5.5]trienones with yields of up to 88%.

The role of dietary chromium supplementation in relieving heat stress of juvenile blunt snout bream Megalobrama amblycephala

The present study assessed the role of dietary chromium (Cr) supplementation in relieving heat stress (HS) of juvenile blunt snout bream Megalobrama amblycephala. The supplemented Cr contents by chromium picolinate (Cr-Pic) was 0 mg/kg (control group), 0.4 mg/kg, 1.6 mg/kg and 12.0 mg/kg, respectively. The fish continued to be fed four diets at suitable temperatures (26 °C) for 2 weeks, and then the temperature was then heated up to 33 °C through thermo-regulated system. The results showed that Cr supplementation had no significant effect on the immune indices and antioxidant indices before HS (P > 0.05). However, Cr supplementation played an important role in relieving HS. After HS, compared with the control group, 1.6 mg/kg and 12.0 mg/kg Cr supplementation groups significantly lowered the plasma glucose level and aspartate transaminase (AST) activity (P < 0.05), and 0.4 mg/kg and 1.6 mg/kg Cr supplementation groups significantly lowered alanine aminotransferase (ALT) activity (P < 0.05). 0.4 mg/kg and 1.6 mg/kg supplementation groups significantly improved hepatic total superoxide dismutase (T-SOD) activity (P < 0.05). Furthermore, 0.4mg/kg-12.0 mg/kg Cr supplementation groups significantly improved the activities of hepatic glutathione peroxidase (GPx) and catalase (CAT) and lowered hepatic malondialdehyde (MDA) level in liver (P < 0.05). The mRNA levels of hepatic copper zinc superoxide dismutase (Cu/Zn-SOD), CAT and GPx were significantly improved in 0.4mg/kg-12.0 mg/kg supplementation Cr groups (P < 0.05), however, there was no significant variation of hepatic manganese superoxide dismutase (Mn-SOD) mRNA levels under different levels of supplementation (P > 0.05). Significantly lower mRNA levels of hepatic pro-inflammatory cytokines observed in 0.4mg/kg-12.0 mg/kg Cr supplementation groups including tumour necrosis factor-α (TNF-α), interleukin 1β (IL-1β) and interleukin 8 (IL-8) (P < 0.05), and 0.4mg/kg-12.0 mg/kg Cr supplementation significantly improved the relative expressions of hepatic heat shock protein 70 (HSP70) and heat shock protein 90 (HSP90) (P < 0.05). The present study indicated that dietary Cr supplementation might have no significant effect on immune capacity and antioxidant capacity under normal physiological conditions, whereas it played an important role in relieving HS.

Optimizing functional near-infrared spectroscopy (fNIRS) channels for schizophrenic identification during a verbal fluency task using metaheuristic algorithms

OBJECTIVE

We aimed to reduce the complexity of the 52-channel functional near-infrared spectroscopy (fNIRS) system to facilitate its usage in discriminating schizophrenia during a verbal fluency task (VFT).

METHODS

Oxygenated hemoglobin signals obtained using 52-channel fNIRS from 100 patients with schizophrenia and 100 healthy controls during a VFT were collected and processed. Three features frequently used in the analysis of fNIRS signals, namely time average, functional connectivity, and wavelet, were extracted and optimized using various metaheuristic operators, i.e., genetic algorithm (GA), particle swarm optimization (PSO), and their parallel and serial hybrid algorithms. Support vector machine (SVM) was used as the classifier, and the performance was evaluated by ten-fold cross-validation.

RESULTS

GA and GA-dominant algorithms achieved higher accuracy compared to PSO and PSO-dominant algorithms. An optimal accuracy of 87.00% using 16 channels was obtained by GA and wavelet analysis. A parallel hybrid algorithm (the best 50% individuals assigned to GA) achieved an accuracy of 86.50% with 8 channels on the time-domain feature, comparable to the reported accuracy obtained using 52 channels.

CONCLUSION

The fNIRS system can be greatly simplified while retaining accuracy comparable to that of the 52-channel system, thus promoting its applications in the diagnosis of schizophrenia in low-resource environments. Evolutionary algorithm-dominant optimization of time-domain features is promising in this regard.

Probing Differences in Gene Essentiality Between the Human and Animal Adapted Lineages of the Mycobacterium tuberculosis Complex Using TnSeq

Members of the Mycobacterium tuberculosis complex (MTBC) show distinct host adaptations, preferences and phenotypes despite being >99% identical at the nucleic acid level. Previous studies have explored gene expression changes between the members, however few studies have probed differences in gene essentiality. To better understand the functional impacts of the nucleic acid differences between Mycobacterium bovis and Mycobacterium tuberculosis, we used the Mycomar T7 phagemid delivery system to generate whole genome transposon libraries in laboratory strains of both species and compared the essentiality status of genes during growth under identical in vitro conditions. Libraries contained insertions in 54% of possible TA sites in M. bovis and 40% of those present in M. tuberculosis, achieving similar saturation levels to those previously reported for the MTBC. The distributions of essentiality across the functional categories were similar in both species. 527 genes were found to be essential in M. bovis whereas 477 genes were essential in M. tuberculosis and 370 essential genes were common in both species. CRISPRi was successfully utilised in both species to determine the impacts of silencing genes including wag31, a gene involved in peptidoglycan synthesis and Rv2182c/Mb2204c, a gene involved in glycerophospholipid metabolism. We observed species specific differences in the response to gene silencing, with the inhibition of expression of Mb2204c in M. bovis showing significantly less growth impact than silencing its orthologue (Rv2182c) in M. tuberculosis. Given that glycerophospholipid metabolism is a validated pathway for antimicrobials, our observations suggest that target vulnerability in the animal adapted lineages cannot be assumed to be the same as the human counterpart. This is of relevance for zoonotic tuberculosis as it implies that the development of antimicrobials targeting the human adapted lineage might not necessarily be effective against the animal adapted lineage. The generation of a transposon library and the first reported utilisation of CRISPRi in M. bovis will enable the use of these tools to further probe the genetic basis of survival under disease relevant conditions.

Compressive and thermally stable boron nitride aerogels as multifunctional sorbents

Boron nitride (BN) aerogels are three-dimensional bulk materials with exceptional performances in a wide range of areas. However, detailed investigations into the relationship of synthesis, structure, and properties are rare. This study demonstrates the feasibility of tuning the performance of the aerogel by simply altering the relative amount of the precursors in the synthesis, which subsequently leads to the formation of aerogels with distinctive properties such as specific surface areas, porosity, and compressibility. The applications of these structurally different aerogels are exemplified by investigating in a series of important industrial-related areas, such as oil absorption/desorption, direct combustion, adsorptive desulfurisation, and CO₂ capture. The study raises the application prospects of BN aerogels in gas-phase catalysis and thermal superinsulation materials.

Tandem vinyl radical Minisci-type annulation on pyridines: one-pot expeditious access to azaindenones

A new regiospecific alkylative/alkenylative cascade annulation of pyridines has been achieved whilst the corresponding classic Minisci alkylative annulation failed. This protocol provides a novel and expeditious access to azaindenones and related compounds via cross-dehydrogenative coupling with the long-standing problem of C2/C4 regioselectivity of pyridines being well addressed.

Identification of an IRES within the coding region of the structural protein of human rhinovirus 16

As an alternative mechanism for cap-dependent (m7GpppN) translation, internal ribosome entry site (IRES)-dependent translation has been observed in the 5' untranslated regions (5' UTR) and coding regions of a number of viral and eukaryotic mRNAs. In this study, a series of 5' terminal truncated structural protein genes that were fused with GFP was used to screen for potential IRESs, and IRESs were identified using a bicistronic luciferase vector or GFP expression vector possessing a hairpin structure. Our results revealed that a putative IRES was located between nt 1982 and 2281 in the VP3 coding region of the human rhinovirus 16 (HRV16) genomes. We also demonstrated that effective IRES-initiated protein expression in vitro did not occur through splicing sites or cryptic promoters. We confirmed that thapsigargin (TG), an inducer of endoplasmic reticulum stress (ERS), facilitated increased IRES activity in a dose-dependent manner. Additionally, the secondary structure of the IRES was predicted online using the RNAfold web server.

Impact of Wetting and Drying Cycles on the Mechanical Properties and Microstructure of Vegetation-growing Concrete

Vegetation-growing Concrete (VC), as a new type of cemented soil, is usually used for plants growing on the surface of high and steep rocky slopes. With the widespread application of VC substrate, a pressing problem arises to ensure its durability under wetting and drying conditions. To explore the greatest possible impact on the mechanical properties and microstructure features of VC substrate, an experimental program including triaxial test, SEM analysis, and ultrasonic testing was implemented. The results showed that wetting and drying cycles can significantly decrease more than 40-percent of peak strength, 60-percent of residual strength, and 50-percent of cohesion for VC substrate under ultimate conditions. The fundamental cause of reduction in mechanical performance was found to be the weakening of the bond between soil particles. And it was discovered that structural damage increased as the number of wetting and drying cycles increased but at a slower rate. Based on the tested results, linear functions between the loss extent parameters of mechanical performance and the structural damage variable were established for the VC substrate. Finally, the action mechanisms of wetting and drying cycles for VC substrate were discussed, and the main influential factors were proposed.

Vegetation Community Characteristics Under Different Vegetation Eco-restoration Techniques at Xiangjiaba Hydropower Station

The objective of this study is to understand the characteristics of vegetation communities under different vegetation eco-restoration models (vegetation concrete eco-restoration technique, frame beam filling soil technique, thick layer base material spraying technique, and external soil spray seeding technique). Vegetation coverage, dominant species, species composition, and species diversity of vegetation community under different vegetation eco-restoration modes were analyzed by field survey. The vegetation community of the abandoned slag slope was unstable due to the simple vegetation community structure. The species and number of the thick layer base material spraying slope were low and fail to form a healthy multilayer community structure due to invade of Leucaena leucocephala (Lam.) de Wit. Studying the allelopathy of Leucaena leucocephala (Lam.) de Wit and seeking the best species composition that can coexist with it is significant to promote the positive succession of the vegetation community. The frame beam filling soil technique, external-soil spray seeding technique, and vegetation concrete eco-restoration technique can effectively promote the succession process of the vegetation community and have well water and soil conservation capacity. These findings suggest that artificial vegetation eco-restoration measures can effectively promote vegetation eco-restoration and the positive succession of vegetation community of disturbed slopes. The research results can provide scientific advice for vegetation eco-restoration and subsequent control and management of disturbed slopes in the Xiangjiaba project, and also can be helpful to other similar projects.

Iron-Catalyzed Dearomatization of Biaryl Ynones with Aldehydes via Double C-H Functionalization in Eco-Benign Solvents: Highly Atom-Economical Synthesis of Acylated Spiro[5.5]trienones

The multiple C-H bonds of biaryl ynones render the 6-exo-trig regioselective C-H activation dearomatization to spiro[5.5]trienones challenging since the competing reactions of C-H bonds on Ar¹ or the ortho-C-H bonds on Ar³ may result in 5-exo-trig cyclization to indenones or 6-exo-trig ortho-dearomatization, respectively. We here report an unprecendented dearomatization of biaryl ynones with aldehydes via double C-H functionalization where a regiospecific remote unactivated para-C-H functionalization of biaryl ynones efficiently furnishes acylated spiro[5.5]trienones. This cascade cyclization features a green catalyst and solvent and high atom- and step-economy.

Maternal butyrate supplementation affects the lipid metabolism and fatty acid composition in the skeletal muscle of offspring piglets

Maternal sodium butyrate (SB) intake has important effects on offspring growth and development. This study aimed to investigate the impacts of maternal SB supplementation during gestation and lactation on fatty acid composition and lipid metabolism in the offspring skeletal muscle of pigs. Twenty sows (Yorkshire, parity 2 to 3) were assigned to the control group (diets without SB, n = 10) and SB group (diets with 0.1% SB, n = 10). The results showed maternal SB supplementation throughout gestation and lactation increased (P < 0.05) body weight of offspring piglets at weaning. The concentrations of triglyceride in plasma and milk were enhanced (P < 0.05). Maternal SB induced (P < 0.05) lipid accumulation with increased expression of peroxisome proliferator activated receptor γ (PPARγ) by enrichment of the acetylation of H3 acetylation K27 (H3K27) in offspring skeletal muscle. Meanwhile, the concentrations of C18:2n-6, C18:3n-3, total polyunsaturated fatty acid (PUFA), n-6 PUFA and n-3 PUFA decreased (P < 0.05) in skeletal muscle of weaning piglets derived from SB sows. Together, these results showed that maternal SB supplementation could influence offspring growth performance, lipid metabolism and fatty acid composition of the skeletal muscle.

Genotype and mutation patterns of macrolide resistance genes of Mycoplasma pneumoniae from children with pneumonia in Qingdao, China, in 2019

OBJECTIVES

This study assessed the incidence and resistance of Mycoplasma pneumoniae (MP) in children in Qingdao, China, in 2019.

METHODS

We detected MP infection in 78 pharyngeal swabs from children with pneumonia by qPCR. The RepMP4 element in the P1 adhesin gene, domain V of the 23S rRNA gene, and the L4/L22 ribosomal proteins were amplified by nested PCR. Evolutionary analysis was conducted based on the P1 gene sequence. Resistance mutations in domain V of the 23S rRNA gene and L4/L22 ribosomal proteins were analysed.

RESULTS

The incidence of MP infection in children with pneumonia was 59.0% (46/78). The mean duration of MP infection was longer than that of non-MP infection. According to P1 gene sequencing of 21 samples, 12 (57.1%) were type 1 and 9 (42.9%) were type 2. Drug resistance mutations A2063G in domain V of 23S rRNA gene and T508C in L22 were identified from all sequenced MP. However, mutations at positions 2064 and 2617 were not found in this study. C162A mutation appeared in most type 2 samples. A430G mutation appeared in one type 1 sample and in several type 2 samples. T279C mutation in L22 was mostly found in type 2 samples.

CONCLUSION

The incidence of MP infection was 59.0% in children with pneumonia in Qingdao in 2019. Type 1 MP infection was slightly more common than type 2, indicating that the genotype of MP is gradually shifting from type 1 to type 2. Macrolide resistance mutation A2063G could be detected in all sequenced MP.

Culture salinity modulates Nrf2 antioxidant signaling pathway and immune response of juvenile Genetically Improved Farmed Tilapia (GIFT) (Oreochromis niloticus) under different dietary protein levels

This study aimed to evaluate that dietary protein levels and culture salinity levels affect the health status of juvenile genetically improved farmed tilapia (GIFT, Oreochromis niloticus). Graded protein levels of six diets were prepared, ranging from 18.20% to 49.49% (dry basis), and were used in cultured GIFT at two salinity levels (0‰ and 8‰) for 8 weeks. The results suggested that appropriate protein levels reduced pro-inflammatory gene expressions in the intestine including interleukin 1β (IL-1β), interleukin 8 (IL-8) and tumour necrosis factor-α (TNF-α) mRNA levels at two salinity levels (P < 0.05). 8‰ salinity significantly decreased the expression levels of IL-1β, TNF-α and nuclear factor-kappa B (NF-κB) (P < 0.05). The anti-inflammatory factor interleukin 10 (IL-10) was significantly increased by 36.42% protein level (P < 0.05). Regarding antioxidant capacity, appropriate protein levels and 8‰ salinity significantly improved the antioxidant capacity of fish by regulating the activities of intestinal total superoxide dismutase (T-SOD), glutathione peroxidase (GPx), and the levels of glutathione (GSH) and malondialdehyde (MDA). Furthermore, appropriate protein levels and 8‰ salinity also significantly enhanced the antioxidant gene expressions associated with the Nrf2/keap1 signaling pathway by regulating the expression levels of heme oxygenase-1 (HO-1), GPx, catalase (CAT) and superoxide dismutase (SOD). According to GPx activities and the mRNA levels of IL-10, the optimum dietary protein levels for GIFT juveniles were 31.12%-32.18% (0‰) and 34.25-35.38% (8‰) based on second-degree polynomial regression analysis. The present study found that appropriate protein levels and 8‰ culture salinity are critical in maintaining the health of GIFT juveniles by improving antioxidant and immune capacity.

Controlling the causative agents of coccidiosis in domestic chickens; an eye on the past and considerations for the future

Coccidiosis is a potentially severe enteritis caused by species of obligate intracellular parasites of the genus Eimeria. These parasites cause significant economic losses to the poultry industry, predominantly due to compromised efficiency of production as well as the cost of control. These losses were recently estimated to cost chicken producers approximately £10.4 billion worldwide annually. High levels of Eimeria infection cause clinical coccidiosis which is a significant threat to poultry welfare, and a pre-disposing contributory factor for necrotic enteritis. Control of Eimeria parasites and coccidiosis is therefore an important endeavour; multiple approaches have been developed and these are often deployed together. This review summarises current trends in strategies for control of Eimeria, focusing on three main areas: good husbandry, chemoprophylaxis and vaccination. There is currently no "perfect solution" and there are advantages and limitations to all existing methods. Therefore, the aim of this review is to present current control strategies and suggest how these may develop in the future.

Facile Synthesis of Electrically Conductive and Heatable Nanoparticle/Nanocarbon Hybrid Aerogels

Joule heating studies on nanoparticle/nanocarbon hybrid aerogels have been reported, but systematic investigations on hydrotalcite-derived catalysts supported onto reduced graphene oxide (rGO) aerogels are rare. In this study, hydrotalcite-derived Cu-Al₂O₃ nanoparticles were incorporated into a porous and multifunctional rGO aerogel support for fabricating electrically conducting Cu-Al₂O₃/rGO hybrid aerogels, and their properties were investigated in detail. The hybridization of Cu-Al₂O₃ with a 3D nanocarbon support network imparts additional functionalities to the widely used functional inorganic nanoparticles, such as direct electrical framework heating and easy regeneration and separation of spent nanoparticles, with well-spaced nanoparticle segregation. 3D variable-range hopping model fitting confirmed that electrons were able to reach the entire aerogel to enable uniform resistive heating. The conductivity of the nanocarbon support framework facilitates uniform and fast heating (up to 636 K/min) of the embedded nanoparticles at very low energy consumption, while the large porosity and high thermal conductivity enable efficient heat dissipation during natural cooling (up to 336 K/min). The thermal stability of the hybrid aerogel was demonstrated by repeated heating/cooling cycling at different temperatures that were relevant to important industrial applications. The facile synthetic approach can be easily adapted to fabricate other types of multifunctional nanoparticle/nanocarbon hybrid aerogels, such as the MgAl-MMO/rGO aerogel and the Ni-Al₂O₃/rGO aerogel. These findings open up new routes to the functionalization of inorganic nanoparticles and extend their application ranges that involve electrical/thermal heating, temperature-dependent catalysis, sorption, and sensing.

Molecular cloning and expression mechanism of Mnp65 in Megalobrama amblycephala response to Aeromonas hydrophilia challenge

p65 is one of the important subunits of the inflammation-related transcription factor NF-κB. In the present study, we cloned and identified the p65 from Megalobrama amblycephala (Mnp65) by homologous cloning and RACE technique. The full-length Mnp65 cDNA consisted of 2331 bp, and included one open reading frame encoding a 604-amino acid putative protein. The protein sequence included a DNA binding motif, a well conserved N-terminal Rel-homology domain (RHD), and a C-terminal IG-like plexins transcription (IPT). Mnp65 was closely related with the other p65 proteins of Cypriniformes and clearly distinct from that of Perciformes and Salmoniformes in terms of sequence homology. Mnp65 homodimer may interact with IκBα in the IPT domain based on the predicted 3D structure of IκBα/Mnp65 complex. Mnp65 was ubiquitously expressed in M. amblycephala tissues, and the highest levels were detected in muscle and liver. Intragastric infection with Aeromonas hydrophila caused respiratory burst and cytokine storm from 8 h to 48 h, showing significantly higher level of respiratory burst activities and significantly high cytokines levels, such as TNF-α, IL-1β, IL-6, IL-8 etc., compared to 0 h. In addition, the bacterial challenge downregulated the IkBα, and upregulated Mnp65 and TNF-α in the liver. IkBα-Mnp65 was regulated by the negative feedback of cytokine storm, to increase IkBα and decrease Mnp65. Then cytokine storm was relieved at 96 h. Finally, severe intestinal inflammation was observed from 24 h to 48 h after infection, characterized by extensive villous necrosis, epithelial hyperplasia and lymphocyte infiltration, all of which were relieved at 96 h. Taken together, Mnp65 plays a crucial role in the physiological response of teleost fish to bacterial infection.

Long Distance Transmission of SARS-CoV-2 from Contaminated Cold Chain Products to Humans - Qingdao City, Shandong Province, China, September 2020

What is already known about this topic?

Though coronavirus disease 2019 (COVID-19) has largely been controlled in China, several outbreaks of COVID-19 have occurred from importation of cases or of suspected virus-contaminated products. Though several outbreaks have been traced to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolated on the outer packaging of cold chain products, live virus has not been obtained.

What is added by this report?

In September 2020, two dock workers were detected as having asymptomatic SARS-CoV-2 infection using throat swabs during routine screening in Qingdao, China. Epidemiological information showed that the two dock workers were infected after contact with contaminated outer packaging, which was confirmed by genomic sequencing. Compared to the Wuhan reference strain, the sequences from the dock workers and the package materials differed by 12-14 nucleotides. Furthermore, infectious virus from the cold chain products was isolated by cell culture, and typical SARS-CoV-2 particles were observed under electron microscopy.

What are the implications for public health practice?

The international community should pay close attention to SARS-CoV-2 transmission mode through cold chain, build international cooperative efforts in response, share relevant data, and call on all countries to take effective prevention and control measures to prevent virus contamination in cold-chain food production, marine fishing and processing, transportation, and other operations.

Molecular characterization and nutritional regulation of sodium-dependent glucose cotransporter 1 (Sglt1) in blunt snout bream (Megalobrama amblycephala)

Fish has poor utilization capacity for glucose metabolism. The possible reasons are related to the core regulatory elements of glucose metabolism: transport proteins. Studies on the species and functions of Sglt1 in aquatic animals are scarce, therefore further studies are needed. In this study, the full length of blunt snout bream (Megalobrama amblycephala) sglt1 (Masglt1) was 2965 bp including 5′-UTR region of 168 bp and a 3′-UTR region of 820 bp. Masglt1 have a highest sequence homology in Cypriniformes fish. MaSglt1 protein was identified as a transmembrane protein with 14 α-helix structures locating plasma membrane by the methods of predicted tertiary structure and immunohistochemical staining. MaSglt1 protein has a hollow channel forms which could be specifically coupled with two Na⁺ ions to recognize glucose and carry out transmembrane transport. High sglt1 mRNA was found in the intestine and kidney. The mRNA levels of intestinal sglt1 had a positive correlation with dietary starch levels at 3 h after feeding, and the mRNA was significantly higher than that at 24 h, however, the mRNA levels of renal sglt1 presented results opposite to those of intestinal sglt1. The mRNA levels of renal sglt1 had a positive correlation with dietary starch levels at 24 h after feeding, and the expression was significantly higher than that at 3 h. These results confirmed that Masglt11 was mainly found in the intestine and kidney and was located in the cell membrane, playing a role in glucose homeostasis.

Effect of flushing temperature on preparation ability of rotary nickel-titanium files

PURPOSE

The effect of flushing at different temperatures on the preparation ability of rotary nickel-titanium files was investigated to provide guideline for clinical application.

METHODS

Sixty ProTaper Universal F1 rotary nickel-titanium files were randomly divided into three groups treated by flushing at 6°C, 23°C, and 40°C. Root canal preparation was conducted by step-by-step method on standardized nickel-titanium instrument fracture models. During preparation, the thrust force was set as 10 N, and water was continuously flushed. The motor speed was 350 rpm (rounds per minute), and the torque was 3.0 N cm. When the set torque was reached, the motor automatically rotated in the reverse direction and was pulled out.

RESULTS

Root canal preparation was performed using ProTaper Universal F1 rotary nickel-titanium files treated by flushing. The numbers of rotations before the device was fracture were 429.33 ± 214.68, 821.92 ± 410.43, and 1304.92 ± 297.81, respectively. When each root canal was completed, the numbers of instrument rotations were 272.15 ± 88.30, 188.85 ± 34.36, and 163.41 ± 16.18, respectively. Rank sum test and analysis of variance were performed by IBM SPSS Statistics v21.0 software, and both of them were p < 0.01, indicating that the number of cycles to failure (NCF) and the number of instrument rotations for each root tube were statistically different at the three temperatures.

CONCLUSIONS

The self-made resin-simulated curved root canal can replace the real root canal to complete the root canal preparation experiment. The group of nickel-titanium files treated by flushing at 23°C can prepare more root canals and prolong the life of nickel-titanium files than at 6°C. When flushing was done at 40°C, the number of root canals prepared by nickel-titanium files was the highest, and it was not easy to damage the instrument, but lateral perforation occurred easily during root canal preparation.

The translocator protein (TSPO) is prodromal to mitophagy loss in neurotoxicity

Dysfunctional mitochondria characterise Parkinson's Disease (PD). Uncovering etiological molecules, which harm the homeostasis of mitochondria in response to pathological cues, is therefore pivotal to inform early diagnosis and therapy in the condition, especially in its idiopathic forms. This study proposes the 18 kDa Translocator Protein (TSPO) to be one of those. Both in vitro and in vivo data show that neurotoxins, which phenotypically mimic PD, increase TSPO to enhance cellular redox-stress, susceptibility to dopamine-induced cell death, and repression of ubiquitin-dependent mitophagy. TSPO amplifies the extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) signalling, forming positive feedback, which represses the transcription factor EB (TFEB) and the controlled production of lysosomes. Finally, genetic variances in the transcriptome confirm that TSPO is required to alter the autophagy-lysosomal pathway during neurotoxicity.

Engineering of Microcage Carbon Nanotube Architectures with Decoupled Multimodal Porosity and Amplified Catalytic Performance

New approaches for the engineering of the 3D microstructure, pore modality, and chemical functionality of hierarchically porous nanocarbon assemblies are key to develop the next generation of functional aerogel and membrane materials. Here, interfacially driven assembly of carbon nanotubes (CNT) is exploited to fabricate structurally directed aerogels with highly controlled internal architectures, composed of pseudo-monolayer, CNT microcages. CNT Pickering emulsions enable engineering at fundamentally different length scales, whereby the microporosity, mesoporosity, and macroporosity are decoupled and individually controlled through CNT type, CNT number density, and process energy, respectively. In addition, metal nanocatalysts (Cu, Pd, and Ru) are embedded within the architectures through an elegant sublimation and shock-decomposition approach; introducing the first approach that enables through-volume functionalization of intricate, pre-designed aerogels without microstructural degradation. Catalytic structure-function relationships are explored in a pharma-important amidation reaction; providing insights on how the engineered frameworks enhance catalyst activity. A sophisticated array of advanced tomographic, spectroscopic, and microscopic techniques reveal an intricate 3D assembly of CNT building-blocks and their influence on the functional properties of the enhanced nanocatalysts. These advances set a basis to modulate structure and chemistry of functional aerogel materials independently in a controlled fashion for a variety of applications, including energy conversion and storage, smart electronics, and (electro)catalysis.

Bioinformatic Analysis of the Campylobacter jejuni Type VI Secretion System and Effector Prediction

The Type VI Secretion System (T6SS) has important roles relating to bacterial antagonism, subversion of host cells, and niche colonisation. Campylobacter jejuni is one of the leading bacterial causes of human gastroenteritis worldwide and is a commensal coloniser of birds. Although recently discovered, the T6SS biological functions and identities of its effectors are still poorly defined in C. jejuni. Here, we perform a comprehensive bioinformatic analysis of the C. jejuni T6SS by investigating the prevalence and genetic architecture of the T6SS in 513 publicly available genomes using C. jejuni 488 strain as reference. A unique and conserved T6SS cluster associated with the Campylobacter jejuni Integrated Element 3 (CJIE3) was identified in the genomes of 117 strains. Analyses of the T6SS-positive 488 strain against the T6SS-negative C. jejuni RM1221 strain and the T6SS-positive plasmid pCJDM202 carried by C. jejuni WP2-202 strain defined the “T6SS-containing CJIE3” as a pathogenicity island, thus renamed as Campylobacter jejuni Pathogenicity Island-1 (CJPI-1). Analysis of CJPI-1 revealed two canonical VgrG homologues, CJ488_0978 and CJ488_0998, harbouring distinct C-termini in a genetically variable region downstream of the T6SS operon. CJPI-1 was also found to carry a putative DinJ-YafQ Type II toxin-antitoxin (TA) module, conserved across pCJDM202 and the genomic island CJIE3, as well as several open reading frames functionally predicted to encode for nucleases, lipases, and peptidoglycan hydrolases. This comprehensive in silico study provides a framework for experimental characterisation of T6SS-related effectors and TA modules in C. jejuni.

[Molecular-related epidemic characteristics of influenza A (H3N2) viruses in Guangzhou, 2019]

Objective: To isolate the influenza A (H3N2) viruses from different sources in Guangzhou in 2019 and analyze these viruses' evolution and variation characteristics. Methods: The hemagglutinin (HA) and neuraminidase (NA) genes of H3N2 isolates from outpatient monitoring, influenza outbreaks, and inpatient severe cases in Guangzhou in 2019 were sequenced. Bioinformatics software analyzed the variations and evolution characteristics of HA and NA genes. Results: The epidemic peaks of influenza A (H3N2) viruses were made up of period Ⅰ (from January to August) and period Ⅱ (from November to December). The positive rate of influenza A (H3N2) in males was 13.46% (703/5 221), which was higher than that in females (11.50%, 510/4 435) (χ²=8.43,P=0.00). The group's positive rate of 10-20 years old was the highest (25.18%,665/2 641). The isolates from different sources were highly homologous and closely related to 3C.2a.1 branches, which could be further divided into three small groups of Group 1-3. Gene recombination was observed between different branches. The mutations of HA antigen sites gradually appeared from Group 1 to Group 3, leading to new antigen drift. Variations of HA antigenic sites mainly occurred in the region of A and B. The mutations of receptor binding sites of Group 1 and Group 3 viruses occurred in the anterior and posterior walls. There were two glycosylation sites lacked on region A of HA antigen observed in the isolates of Group 2-3. Conclusions: Genetic variations of H3N2 influenza viruses in Guangzhou included gene mutations and gene recombination. Under the pressure of the vaccine, the evolution of viruses was rapid. Therefore, the monitoring of molecular-related epidemic characteristics of the H3N2 influenza virus was necessary.

Alkylative Dearomatization by Using an Unactivated Aryl Nitro Group as a Leaving Group: Access to Diversified Alkylated Spiro[5.5]trienones

The cleavage of an unactivated aryl nitro group triggered by alkyl radicals enables a dearomative cyclization, affording diversified alkylated spiro[5.5]trienones in good yields. Using readily available compounds (toluene and analogues, alkanes, ethers, ketones, etc.) as alkylating reagents, various alkyls have been implanted into the spirocycles via C(sp³)-H and Ar-NO₂ bond activation with high functional group tolerance. This protocol provides a distinct method for the activation of the aryl nitro group.

Analysis of Cryptosporidium spp. from clinical samples by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry

AIM

To purify Cryptosporidium spp. oocysts from clinical stool samples and evaluate using an up-to-date mass spectrometry protocol producing high-quality reference spectra.

METHODS AND RESULTS

A refined purification protocol was developed for oocysts from stools, involving salt flotation and potassium bromide density centrifugation. Purified oocysts were prepared for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) by formic acid extraction, and the extracts analysed using the Bruker MALDI Biotyper system. Individual spectral markers were identified by their specific mass peaks. Cryptosporidium parvum oocysts (Iowa strain) propagated in vivo, and C.  parvum (n = 2) and Cryptosporidium hominis (n = 1) oocysts from clinical stool samples produced distinct spectra that were considered specific to Cryptosporidium spp. with no evidence of contamination.

CONCLUSIONS

The production of distinct spectra demonstrated the utility of the purification method for oocysts from clinical stool samples and provided reference spectra.

SIGNIFICANCE AND IMPACT OF THE STUDY

The use of MALDI-TOF MS and other mass spectrometry techniques has been limited previously to C.  parvum oocysts propagated in vivo. Appropriate purification of oocysts can achieve sufficient biomass, enabling analysis by MALDI-TOF MS and potentially other mass spectrometry platforms, facilitating peptide and protein discovery and identification of biomarkers from a much wider range of Cryptosporidium spp. from natural infections.

Accuracy of history, physical examination, cardiac biomarkers, and biochemical variables in identifying dogs with stage B2 degenerative mitral valve disease

Background

Treatment is indicated in dogs with preclinical degenerative mitral valve disease (DMVD) and cardiomegaly (stage B2). This is best diagnosed using echocardiography; however, relying upon this limits access to accurate diagnosis.

Objectives

To evaluate whether cardiac biomarker concentrations can be used alongside other clinical data to identify stage B2 dogs.

Animals

Client‐owned dogs (n = 1887) with preclinical DMVD prospectively sampled in Germany, the United Kingdom, and the United States.

Methods

Dogs that met inclusion criteria and were not receiving pimobendan (n = 1245) were used for model development. Explanatory (multivariable logistic regression) and predictive models were developed using clinical observations, biochemistry, and cardiac biomarker concentrations, with echocardiographically confirmed stage B2 disease as the outcome. Receiver operating characteristic curves assessed the ability to identify stage B2 dogs.

Results

Age, appetite, serum alanine aminotransferase activity, body condition, serum creatinine concentration, murmur intensity, and plasma N‐terminal propeptide of B‐type natriuretic peptide (NT‐proBNP) concentration were independently associated with the likelihood of being stage B2. The discriminatory ability of this explanatory model (area under curve [AUC], 0.84; 95% confidence interval [CI], 0.82‐0.87) was superior to NT‐proBNP (AUC, 0.77; 95% CI, 0.74‐0.80) or the vertebral heart score alone (AUC, 0.76; 95% CI, 0.69‐0.83). A predictive logistic regression model could identify the probability of being stage B2 (AUC test set, 0.86; 95% CI, 0.81‐0.91).

Conclusion and Clinical Importance

Our findings indicate accessible measurements could be used to screen dogs with preclinical DMVD. Encouraging at‐risk dogs to seek further evaluation could result in a greater proportion of cases being appropriately managed.

Transcriptomic Profiling of In Vitro Tumor-Stromal Cell Paracrine Crosstalk Identifies Involvement of the Integrin Signaling Pathway in the Pathogenesis of Mesenteric Fibrosis in Human Small Intestinal Neuroendocrine Neoplasms

Aim

Analysis of the pathophysiology of mesenteric fibrosis (MF) in small intestinal neuroendocrine tumors (SI-NETs) in an in vitro paracrine model and in human SI-NET tissue samples.

Methods

An indirect co-culture model of SI-NET cells KRJ-I and P-STS with stromal cells HEK293 was designed to evaluate the paracrine effects on cell metabolic activity, gene expression by RT2 PCR Profilers to analyse cancer and fibrosis related genes, and RNA sequencing. The integrin signaling pathway, a specific Ingenuity enriched pathway, was further explored in a cohort of human SI-NET tissues by performing protein analysis and immunohistochemistry.

Results

RT Profiler array analysis demonstrated several genes to be significantly up- or down-regulated in a cell specific manner as a result of the paracrine effect. This was further confirmed by employing RNA sequencing revealing multiple signaling pathways involved in carcinogenesis and fibrogenesis that were significantly affected in these cell lines. A significant upregulation in the expression of various integrin pathway – related genes was identified in the mesenteric mass of fibrotic SI-NET as confirmed by RT-qPCR and immunohistochemistry. Protein analysis demonstrated downstream activation of the MAPK and mTOR pathways in some patients with fibrotic SI-NETs.

Conclusion

This study has provided the first comprehensive analysis of the crosstalk of SI-NET cells with stromal cells. A novel pathway – the integrin pathway – was identified and further validated and confirmed in a cohort of human SI-NET tissue featured by a dual role in fibrogenesis/carcinogenesis within the neoplastic fibrotic microenvironment.

Understanding the Joule-heating behaviours of electrically-heatable carbon-nanotube aerogels

Cylindrical monolithic, electrically-heatable reduced carbon nanotube (rCNT) aerogels were synthesized to exploit their Joule-heating behaviours using two different arrangements (i.e. the top-bottom arrangement and the side-side arrangement) under different compressive strains. The top-bottom arrangement results in faster heating kinetics (up to 286 K min^-1), higher heating efficiency (up to 80 °C W^-1), a more uniform temperature distribution profile and higher electro-thermal conversion efficiency than the side-side arrangement. This study provides fundamental perspectives for exploiting the Joule-heating behaviours of geometrically complex nanocarbon aerogels, and thus will have important implications in strain-sensitive materials.

On-line spectroscopic study of brominated flame retardant extraction in supercritical CO2

Removal of brominated flame retardants (BFRs) from polymers before disposal or recycling will alleviate negative environmental effects and ensure safe usage of recycled products. Extraction of BFRs in supercritical CO₂ is appealing but also presents challenges to industries due to limited solubility and lack of kinetic studies. For a more comprehensive evaluation of supercritical extraction potentialities, we (i) developed an on-line pressure apparatus that is compatible with both the FTIR and UV-vis spectrometers to enable kinetic and thermodynamic studies; (ii) studied kinetic extraction involving three conventional and two novel BFRs as well as three typical polymeric matrix. Solubilities were determined using the gravimetric method or X-ray fluorescence. FTIR exhibited a superior applicability compared to UV-vis in the following BFR extraction's time-dependency binary and ternary systems. We observed that faster stirring speed, higher temperature, and finer particle size can accelerate the overall extraction kinetics. In binary systems, it took less than 2 h to achieve equilibrium for each BFR at 60 °C, 25 MPa and 1000 rpm. In the presence of polymeric matrix, slower extraction kinetics were observed due to the occurrence of competitive dissolution and molecular diffusion within the matrix. Mathematical models derived from irreversible desorption and Fick's diffusion laws fitted well with the observed extraction kinetics of BFRs, thus enabling us to identify the rate-determining step. The high solubilization rate coefficients that we measured for BFRs revealed that the dynamic extraction process in up-scaling design could compensate for the low solubility with flowing supercritical CO₂.

Mitochondria form contact sites with the nucleus to couple prosurvival retrograde response

Mitochondria drive cellular adaptation to stress by retro-communicating with the nucleus. This process is known as mitochondrial retrograde response (MRR) and is induced by mitochondrial dysfunction. MRR results in the nuclear stabilization of prosurvival transcription factors such as the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Here, we demonstrate that MRR is facilitated by contact sites between mitochondria and the nucleus. The translocator protein (TSPO) by preventing the mitophagy-mediated segregation o mitochonria is required for this interaction. The complex formed by TSPO with the protein kinase A (PKA), via the A-kinase anchoring protein acyl-CoA binding domain containing 3 (ACBD3), established the tethering. The latter allows for cholesterol redistribution of cholesterol in the nucleus to sustain the prosurvival response by blocking NF-κB deacetylation. This work proposes a previously unidentified paradigm in MRR: the formation of contact sites between mitochondria and nucleus to aid communication.

Lysine acetylation participates in boar spermatozoa motility and acrosome status regulation under different glucose conditions

Efficient artificial insemination (AI) with liquid preserved boar semen is essential for the swine industry. Glucose is the most widely utilized energy source in refrigerated boar semen extenders. However, the relationship between glucose concentration and spermatozoa quality is not fully understood. In the present study, boar spermatozoa were used as a model to investigate the impact of different glucose concentrations on spermatozoa motility, mitochondrial activity, and acrosome integrity at physiological temperature (37 °C) and during refrigeration (17 °C). The proportion of progressively motile spermatozoa and mitochondrial activity in the high glucose group were significantly lower than in the low glucose group when incubated at 37 °C for 3 h or 17 °C for 3 d, but not at 17 °C for 7 d. Lysine acetylation is a reversible post-translational modification that plays a crucial role in spermatozoa function. Our results show that spermatozoa protein acetylation levels were higher in the high glucose group than in the low glucose group. The proportions of progressively motile and acrosome-intact spermatozoa were higher in acetyltransferase inhibitor (WM-1119)-treated spermatozoa than in the control. Spermatozoa acetyl-CoA concentration, which is directly linked to acetylation, was significantly higher in the high glucose group than in the low glucose group. Taken together, spermatozoa motility and acrosome integrity can be altered by changing the concentration of glucose in the extender. High glucose concentration-induced lysine acetylation participates in the regulation of boar spermatozoa motility and acrosome integrity during preservation. These results can provide insights into spermatozoa preservation and AI in the swine industry.

The Growth of Eimeria tenella: Characterization and Application of Quantitative Methods to Assess Sporozoite Invasion and Endogenous Development in Cell Culture

In vitro development of the complete life cycle of Eimeria species has been achieved in primary cultures of avian epithelial cells with low efficiency. The use of immortalized cell lines simplifies procedures but only allows partial development through one round of parasite invasion and intracellular replication. We have assessed the suitability of Madin-Darby Bovine Kidney (MDBK) cells to support qualitative and quantitative studies on sporozoite invasion and intracellular development of Eimeria tenella. Analysis of parasite ultrastructure by transmission electron microscopy and serial block face-scanning electron microscopy proved the suitability of the system to generate good quality schizonts and first-generation merozoites. Parasite protein expression profiles elucidated by mass spectrometry corroborated previous findings occurring during the development of the parasite such as the presence of alternative types of surface antigen at different stages and increased abundance of proteins from secretory organelles during invasion and endogenous development. Quantitative PCR (qPCR) allowed the tracking of development by detecting DNA division, whereas reverse transcription qPCR of sporozoite- and merozoite-specific genes could detect early changes before cell division and after merozoite formation, respectively. These results correlated with the analysis of development using ImageJ semi-automated image analysis of fluorescent parasites, demonstrating the suitability and reproducibility of the MDBK culture system. This systems also allowed the evaluation of the effects on invasion and development when sporozoites were pre-incubated with anticoccidial drugs, showing similar effects to those reported before. We have described through this study a series of methods and assays for the further application of this in vitro culture model to more complex studies of Eimeria including basic research on parasite cell biology and host-parasite interactions and for screening anticoccidial drugs.

The Microbiome-Metabolome Response in the Colon of Piglets Under the Status of Weaning Stress

Weaning is stressful for piglets involving nutritional, physiological, and psychological challenges, leading to an increase in the secretion of cortisol, changes in gut microbiome and metabolites, whereas the underlying relationships remain unclear. To elucidate this, 14 Meishan female piglets were divided into the weaning group and the suckling group at the age of 21 days paired by litter and body weight. After 48 h of experiment, weaned piglets had lower body weight, but higher salivary cortisol level than that of their suckling litter mates (P < 0.05). The composition of the colonic bacterial community and metabolites were different between the two groups, and the first predominant genus of the suckling and weaned piglets colonic microbiome were Bacteroides and Prevotellaceae-NK3B31 group respectively. The suckling piglets had higher proportions of phylum Bacteroidetes and Lentisphaerae, and genus Bacteroides and Lactobacillus in the colonic microbial community, but lower abundance of genus Prevotellaceae-NK3B31 group than that of the weaned piglets (P < 0.05). Accordingly, there were 15 colonic metabolites differed between the two groups, in which 2 metabolites (phenylacetic acid and phenol) negatively related to the abundant of Lactobacillus genus (P < 0.05), while 9 metabolites (acetic acid, arabitol, benzoic acid, caprylic acid, cholesterol, dihydrocholesterol, galactinol, glucose phenol, phenylacetic acid, and oxamic acid, glycerol, propionic acid) positively associated with the proportion of Prevotellaceae-NK3B31 group genus (P < 0.05). Furthermore, the salivary cortisol level negatively associated with the abundance of phylum Lentisphaerae, but positively associated with the phylum Bacteroidetes and the genus Prevotellaceae-NK3B31 group (P < 0.05) respectively. These results provide us with new insights into the cause of the gut microbiome and stress, and the contributions of gut microbiome in metabolic and physiological regulation in response to weaning stress.

Phylogenetic Inference Using Cytochrome C Oxidase Subunit I (COI) in the Poultry Red Mite, Dermanyssus gallinae in the United Kingdom Relative to a European Framework

The poultry red mite (Dermanyssus gallinae), an obligatory blood feeding ectoparasite, is primarily associated with laying hens where it is estimated to cause losses of ~€231 million per annum to European farmers. Moderate to high infestation levels result in negative impacts on hen welfare, including increased cannibalism, irritation, feather pecking, restlessness, anemia, and mortality. Acaricides are currently the prevailing method of population control for D. gallinae, although resistance against some classes of acaricide has been widely reported. The development of resistance highlights a growing need for research into alternative control methods, including the development of a suitable and effective vaccine. Understanding the genetic structure of D. gallinae populations can support improved management of acaricide resistance and sustainability of future vaccines, but limited data are currently available. The aim of this study was to characterize D. gallinae isolates from Europe, targeting the cytochrome c oxidase subunit 1 (COI) gene to gain an insight into population structure and genetic diversity of currently circulating mites. Dermanyssus gallinae isolates were collected from Albania, Belgium, Croatia, Czech Republic, Denmark, France, Greece, Italy, the Netherlands, Portugal, Romania, Slovenia, Turkey and the United Kingdom. Genomic DNA was extracted from individual adult D. gallinae mites and a 681bp fragment of the COI gene was amplified and sequenced. Phylogenetic analyses of 195 COI sequences confirmed the presence of multiple lineages across Europe with 76 distinct haplotypes split across three main haplogroups and six sub-haplogroups. Importantly there is considerable inter- and intra-country variation across Europe, which could result from the movement of poultry or transfer of contaminated equipment and/or materials and husbandry practices.

The facile and additive-free synthesis of a cell-friendly iron(iii)-glutathione complex

The straightfoward creation of an unreported glutathione-stabilised iron(iii) complex is disclosed. In contrast to previous reports, glutathione was shown to coordinate and stabilise iron directly under physiological conditions in the absence of additional sulfur containing molecules, such as sodium sulfide. The complex was extensively characterised; the molecular geometry was determined as two inequivalent octahedra, approximately 2/3 of which are slightly distorted towards more tetrahedral in character, with the remaining 1/3 more regularly octahedral. The dispersion of the iron(iii)-glutathione complex in aqueous solution yielded particles of 255 ± 4 nm in diameter that enhanced the growth and proliferation of L929 fibroblast cells over 7 days, and inhibited the activity of matrix metalloproteinase-13. Consequently, the unprecedented glutathione-stabilised iron(iii) complex disclosed has potential use as a simple-to-prepare growth factor for inclusion within cell culture media, and is an excellent candidate as a therapeutic for the treatment of metalloproteinase-13-associated diseases.