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1.
Mult Scler Relat Disord ; 49: 102779, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33524926

RESUMO

BACKGROUND: Inosine monophosphate dehydrogenase-1 is the target of mycophenolate mofetil. This research investigated the association between the gene polymorphism of inosine monophosphate dehydrogenase-1 and effectiveness of mycophenolate mofetil therapy in neuromyelitis optica spectrum disorder patients. METHODS: Fifty-nine neuromyelitis optica spectrum disorder patients accepted Mycophenolate Mofetil therapy for 1 year at least were divided into two groups: relapsing (n=21) and non-relapsing (n=38). Four single-nucleotide polymorphisms (SNPs: rs2228075, rs2278294, rs2288550, and rs3793165) in the inosine monophosphate dehydrogenase-1 gene were detected. Then we analyzed the allelic frequencies and the genotypes of SNPs in two groups. RESULTS: The allelic frequency of rs2278294 distributed differently between the relapse and non-relapsing patients (P=0.03), while no significant difference found in rs2228075, rs2288550 and rs3793165 between two groups. The genotypes C/C, C/T and T/T of rs2278294 (P = 0.031) also distributed differently between the two groups. Logistic regression analysis (adjusted by optic neuritis) showed that compared to the wild genotype C/C, C/T genotype had a 9-fold protection against relapse (OR=0.111 (0.022-0.548)), and T/T genotype had a 6.7-fold protection against relapse (OR=0.149 (0.026-0.854)). CONCLUSION: Our study provides preliminary evidence that the genotype of rs2278294 is associated with the response of neuromyelitis optica spectrum disorder patients to mycophenolate mofetil therapy. And compared to wild allelic C, the mutation to T tended to respond better to MMF.

2.
ACS Nano ; 2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33533242

RESUMO

Long-distance walking with heavy loads is often needed when going hiking or for field rescue, which is prone to cumulative fatigue. There is also a great need for labor-saving and biomechanical energy harvesting in daily life for extended security and communication needs. Here, we report a load-suspended backpack for harvesting the wasted energy of human motion based on a triboelectric nanogenerator (TENG). Two elastomers are incorporated into the backpack to decouple the synchronous movement of the load and the human body, which results in little or no extra accelerative force. With such a design, through theoretical analysis and field experiments, the backpack can realize a reduction of 28.75 % in the vertical oscillation of the load and 21.08 % in the vertical force on the wearer, respectively. Meanwhile, the mechanical-to-electric energy conversion efficiency is modeled and calculated to be 14.02 % under normal walking conditions. The designed backpack has the merits of labor-saving and shock absorption as well as electricity generation, which has the promising potential to be a power source for small-scale wearable and portable electronics, GPS systems, and other self-powered health care sensors.

3.
Sci Adv ; 7(6)2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33547071

RESUMO

To characterize the genetic basis of facial features in Latin Americans, we performed a genome-wide association study (GWAS) of more than 6000 individuals using 59 landmark-based measurements from two-dimensional profile photographs and ~9,000,000 genotyped or imputed single-nucleotide polymorphisms. We detected significant association of 32 traits with at least 1 (and up to 6) of 32 different genomic regions, more than doubling the number of robustly associated face morphology loci reported until now (from 11 to 23). These GWAS hits are strongly enriched in regulatory sequences active specifically during craniofacial development. The associated region in 1p12 includes a tract of archaic adaptive introgression, with a Denisovan haplotype common in Native Americans affecting particularly lip thickness. Among the nine previously unidentified face morphology loci we identified is the VPS13B gene region, and we show that variants in this region also affect midfacial morphology in mice.

4.
Bioinformatics ; 2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33492356

RESUMO

MOTIVATION: Multiple events extraction from biomedical literature is a challenging task for biomedical community. Usually, biomedical event extraction is modeled as two sub-tasks, trigger identification and argument detection. Most existing methods perform these two sub-tasks sequentially, and fail to make full use of the interaction between them, leading to suboptimal results for multiple biomedical events extraction. METHOD: We propose a novel framework of reinforcement learning (RL) for the task of multiple biomedical events extraction. More specifically, trigger identification and argument detection are treated as main-task and subsidiary-task, respectively. Assigning the event type of triggers (in the main-task) is viewed as the action taken in RL, and the result of corresponding argument detection (i.e. the subsidiary-task) for the identified trigger is used for computing the reward of the taken action. Moreover, the result of the subsidiary-task is modeled as part of environment information in RL to help the procedure of trigger identification. In addition, external biomedical knowledge bases are employed for representation learning of biomedical text, which can improve the performance of biomedical event extraction. RESULTS: Results on two widely used biomedical corpora demonstrate that the proposed framework performs better than the selected baselines on the task of multiple events extraction. The ablation test indicates the contributions of RL and external KBs to the performance improvement in the proposed method. In addition, by modeling multiple events extraction under the RL framework, the supervised information is exploited more effectively than the classical supervised learning paradigm.

5.
Eur Neurol ; : 1-9, 2021 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-33498046

RESUMO

INTRODUCTION: Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) syndrome is a recently described chronic inflammatory disease of the central nervous system. There are few reports of CLIPPERS in the Chinese population to date. We summarized the clinical characteristics of 6 CLIPPERS patients to deepen the understanding of this disease. METHODS: The clinical manifestations and treatment of 6 CLIPPERS patients confirmed by pathology or clinical diagnosis in our hospital were retrospectively analyzed. RESULTS: The common clinical manifestations included ataxia, dysarthria, diplopia, dysphagia, dizziness, cognitive impairment, facial paresthesia, and paralysis. Most of the lesions showed typical symmetric "pepper powder"-like dot and nodular enhancement centered in the pontine and cerebellum except 1 patient with unilateral nodular enhancement. The brain histopathological examination of the 5 biopsied patients indicated that, with the exception of patient 4 with no lymphocyte infiltration, a large amount of perivascular lymphocytic infiltration was found in the other 4 patients, among whom only 1 patient was dominated by CD3+ T cell infiltration and the other 3 patients were dominated by CD20+ B cell infiltration. After treatment with intravenous methylprednisolone, all patients had significant clinical recovery associated with complete or significant MRI recovery, but they were prone to relapse after withdrawal or reduction of the corticosteroid. CONCLUSION: Our reports highlight the importance of neuropathological examinations when encountering atypical imaging manifestations, such as unilateral and large nodular Gd+ lesions, in order to establish a final diagnosis of CLIPPERS. In addition, the lymphocytic infiltration in the lesions of CLIPPERS may be dominated by CD20+ B cells instead of CD3+ T cells.

6.
Genome Biol ; 22(1): 18, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33402197

RESUMO

BACKGROUND: Although the genomes of monozygotic twins are practically identical, their methylomes may evolve divergently throughout their lifetime as a consequence of factors such as the environment or aging. Particularly for young and healthy monozygotic twins, DNA methylation divergence, if any, may be restricted to stochastic processes occurring post-twinning during embryonic development and early life. However, to what extent such stochastic mechanisms can systematically provide a stable source of inter-individual epigenetic variation remains uncertain until now. RESULTS: We enriched for inter-individual stochastic variation by using an equivalence testing-based statistical approach on whole blood methylation microarray data from healthy adolescent monozygotic twins. As a result, we identified 333 CpGs displaying similarly large methylation variation between monozygotic co-twins and unrelated individuals. Although their methylation variation surpasses measurement error and is stable in a short timescale, susceptibility to aging is apparent in the long term. Additionally, 46% of these CpGs were replicated in adipose tissue. The identified sites are significantly enriched at the clustered protocadherin loci, known for stochastic methylation in developing neurons. We also confirmed an enrichment in monozygotic twin DNA methylation discordance at these loci in whole genome bisulfite sequencing data from blood and adipose tissue. CONCLUSIONS: We have isolated a component of stochastic methylation variation, distinct from genetic influence, measurement error, and epigenetic drift. Biomarkers enriched in this component may serve in the future as the basis for universal epigenetic fingerprinting, relevant for instance in the discrimination of monozygotic twin individuals in forensic applications, currently impossible with standard DNA profiling.

7.
Metabolism ; 114: 154412, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33164859

RESUMO

BACKGROUND: The delayed repair process in the aging diabetic population is becoming an alarming public health concern. ICAM-1 plays an important role in orchestrating the repair process by mediating neutrophil recruitment and phagocytosis. However, little is known about the role of ICAM-1 in aging diabetic repair. METHODS: By causing injury in aging diabetic mice with ICAM-1 deletion (AD-ICAM-1-/-), we found that AD-ICAM-1-/- mice exhibited a delayed repair process with incomplete re-epithelialization and reduced angiogenesis. Additionally, high-throughput Illumina sequencing was performed to evaluate the microbiota of such mice. RESULTS: The results indicate that the microbiota of the AD-ICAM-1-/- injury site differed taxonomically at both the phylum and genus levels. Neutrophil recruitment and phagocytic function were also reduced in the AD-ICAM-1-/- group. Notably, major inflammatory biomarker expression was also detected in AD-ICAM-1-/- injured tissue. CONCLUSIONS: Overall, this study demonstrated that AD-ICAM-1-/- mice exhibit delayed repair. In addition, neutrophil recruitment and phagocytic activity were impaired in the AD-ICAM-1-/- group, which may have allowed microbes to colonize the injury site.


Assuntos
Envelhecimento/metabolismo , Diabetes Mellitus Experimental/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo , Infiltração de Neutrófilos/fisiologia , Animais , Movimento Celular/fisiologia , Molécula 1 de Adesão Intercelular/genética , Camundongos , Camundongos Knockout , Microbiota , Fagocitose/fisiologia
8.
Biosci Rep ; 41(1)2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33345265

RESUMO

Cobalt nanoparticles (CoNPs) released from hip joint implants are known to have a toxic effect on several organs probably through increasing reactive oxygen species (ROS). Ferrous ion (Fe2+) is well-known to enhance oxidative stress by catalysing the production of ROS. However, in our pilot study, we found that Fe2+ conversely inhibited the ROS production induced by CoNPs. To elucidate the underlying mechanism, the present study treated vascular endothelial HUVEC and HMEC-1 cells with CoNPs alone or in combination with ferrous lactate [Fe(CH3CHOHCOO)2], ferrous succinate [Fe(CH2COO)2], and ferrous chloride (FeCl2). CoNP toxicity was evaluated by measuring cell viability, rate of apoptosis and lactose dehydrogenase (LDH) release, and intracellular ROS levels. Treatment with CoNPs decreased cell viability, LDH release, and ROS production and increased apoptosis. CoNPs increased hypoxia-inducible factor-1α (HIF-1α) protein level and mRNA levels of vascular endothelial growth factor (VEGF) and glucose transporter 1 (GLUT1) downstream of HIF-1α signalling. Silencing HIF-1α attenuated CoNP toxicity, as seen by recovery of cell viability, LDH release, and ROS levels and reduced apoptosis. CoNPs caused a pronounced reduction of Fe2+ in cells, but supplementation with Fe(CH3CHOHCOO)2, Fe(CH2COO)2, and FeCl2 restored Fe2+ levels and inhibited HIF-1α activation. Moreover, all three Fe2+-containing agents conferred protection from CoNPs; Fe(CH3CHOHCOO)2 and Fe(CH2COO)2 more effectively than FeCl2. In summary, the present study revealed that CoNPs exert their toxicity on human vascular endothelial cells by depleting intracellular Fe2+ level, which causes activation of HIF-1α signalling. Supplements of Fe2+, especially in the form of Fe(CH3CHOHCOO)2 and Fe(CH2COO)2, mitigated CoNP toxicity.

9.
Nat Commun ; 11(1): 6163, 2020 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-33268787

RESUMO

Long noncoding RNAs are thought to regulate gene expression by organizing protein complexes through unclear mechanisms. XIST controls the inactivation of an entire X chromosome in female placental mammals. Here we develop and integrate several orthogonal structure-interaction methods to demonstrate that XIST RNA-protein complex folds into an evolutionarily conserved modular architecture. Chimeric RNAs and clustered protein binding in fRIP and eCLIP experiments align with long-range RNA secondary structure, revealing discrete XIST domains that interact with distinct sets of effector proteins. CRISPR-Cas9-mediated permutation of the Xist A-repeat location shows that A-repeat serves as a nucleation center for multiple Xist-associated proteins and m6A modification. Thus modular architecture plays an essential role, in addition to sequence motifs, in determining the specificity of RBP binding and m6A modification. Together, this work builds a comprehensive structure-function model for the XIST RNA-protein complex, and suggests a general strategy for mechanistic studies of large ribonucleoprotein assemblies.

10.
Ying Yong Sheng Tai Xue Bao ; 31(11): 3665-3673, 2020 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-33300716

RESUMO

Accurate measurement of CO2 storage flux (Fs) in forest ecosystems is of great significance for estimating ecosystem carbon budget by eddy covariance (EC). The errors in the estimation of ecosystem carbon budget caused by different methods for calculating Fs has yet not been comprehensively assessed. Using data from an open-path EC system and an eight-level CO2/H2O profile system (AP100, Campbell Scientific Inc., USA) in a broadleaved deciduous forest at the Maoer-shan in 2018, we evaluated the methodological effect of Fs[2-min mean profile (P2 min), 30-min mean profile (P30 min) and 30-min mean EC single point (Ps)] on the estimation of net ecosystem exchange (NEE), ecosystem respiration (Re), and gross primary productivity (GPP). The results showed that the impact of Fs methods on forest carbon flux generally increased with the increases of time scale, indicating that gap-filling of flux data would further amplify the impacts of Fs estimation methods. At the annual scale, NEE based on P2 min and Ps methods were 36.3% and 29.4% lower than that based on P30 min, while Re based on P2 min was higher than that based on P30 min and Ps by 8.7%. The GPP based on P2 min was 5.4% higher, while that based on Ps was 2.1% lower than that based on P30 min. The traditional P30 min ignored the instantaneous changes in CO2 concentration, Ps missed the changes of CO2 concentration within canopy, and thus both underestimated the actual Re. The approximately instantaneous profile (2-min mean profile) had higher temporal and spatial resolution and could more accurately estimate forest carbon budget with non-flat terrain and complex canopy structure. Our findings had great implications for solving the underestimation of forest Re and GPP as well as the overestimation of net carbon sink on complex conditions with the EC method.

11.
Mol Genet Genomic Med ; : e1582, 2020 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-33369188

RESUMO

BACKGROUND: Gabriele-de Vries syndrome (GADEVS), also known as YY1 haploinsufficiency syndrome, is a very rare autosomal dominant neurodevelopmental disorder (NDD) due to YY1 mutation characterized by mild-to-profound developmental delay (DD)/intellectual disability (ID), a wide spectrum of functional and morphologic abnormalities, and intrauterine growth restriction or low birth weight and feeding difficulties are common in the patients. However, NDDs, such as language development disorder and ID, could hardly be assessed in patients younger than 2 years old. METHODS: We describe a 9-month-old female with DD, failure to thrive, and facial dysmorphism. Genetic analysis was conducted by whole exome sequencing (WES) and confirmed by Sanger sequencing. RESULTS: In addition to DD and dysmorphic facial features, this patient had urinary tract infection, acute pyelonephritis, bilateral vesicoureteral reflux (grade III), gastroesophageal reflux, and malnutrition. She was found to have foramen ovale or atrial septal defect, and enlarged left lateral ventricle in the brain. After performing WES, a novel heterozygous mutation NM_003403.5:c.1124G>A, p.Arg375Gln in the YY1 gene was identified. CONCLUSION: Our findings suggest that genetic tests are critical technique for diagnosis of GADEVS, especially in patients with early-childhood, unexplained developmental or growth disorders, thus, the prevalence of GADEVS may be underestimated. The clinical features and identified YY1 mutation in our patient expand the spectra of phenotypes and genotypes of GADEVS, respectively.

12.
Artigo em Inglês | MEDLINE | ID: mdl-33316964

RESUMO

With the outbreak of novel coronavirus in 2019, most universities changed from traditional offline teaching to online teaching, which brought about a large amount of problems, including teachers' physical and mental problems. Because of teaching on the computer screen for a long period of time, the teacher lacks communication and can act casually. With long-term accumulation, the problem of teachers' job burnout has become increasingly serious. The main purpose of this study was to examine the influence of professional identity on job burnout during the period of the novel coronavirus. At the same time, this study also discussed the moderating effect of job satisfaction on professional identity and job burnout, and its relationship between job satisfaction and job burnout. During the peak period of the COVID-19 epidemic, we conducted an online survey-483 Chinese university teachers with online teaching experience completed the Teacher Professional Identity Scale, Job Satisfaction Scale, and Job Burnout Scale. The results of this study found professional identity and job satisfaction of university teachers to be significantly negative predictors of job burnout, with job satisfaction playing a moderating role between professional identity and job burnout. This study also confirmed that professional identity and job satisfaction are important factors affecting job burnout of university teachers. Therefore, this study proposed that schools should adopt more effective strategies to improve university teachers' professional identity and job satisfaction in order to reduce the practical problems of job burnout, ensure the effectiveness of online teaching, and maintain the sustainable development during the epidemic.


Assuntos
Esgotamento Profissional , Docentes , Satisfação no Emprego , Pandemias , Esgotamento Profissional/epidemiologia , China , Humanos , Inquéritos e Questionários , Universidades
13.
Nanotechnology ; 2020 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-33361573

RESUMO

Precise control of structure and bonds in doped carbon dots (CDs) is siginificant to tune their fluorescence as desired. Up to now, it still lacks effective ways to control the bonds of doped CDs. In this article, we showed that the fluorescence of B/N-doped carbon dots (B/N-CDs) could be precisely tuned just by controlling precursor pH values. As-prepared B/N-CDs exhibit two emission bands, including one emission peak around 450 nm from the defect state from low sp2 hybridization of carbon atoms as well as the other emission peak around 360nm from the B-N bond. The results of the ratio of the maximum intensity of the two emission peaks above show a linear relationship. Meanwhile, the role of pH value of precursor on the luminescence of B/N-CDs is deeply studied. On the one hand, the pH value affects the bonding process of CDs. N-H bonds tend to form at a low pH value while more competitive of B-N bonds exist at much higher pH value, leading to the pH-dependent intensity for 360nm emission band. On the other hand, a high pH value will cause higher crystallinity, thus suppressing the defect state fluorescence at 450nm.The dual effects of pH lead to precisely controlled dual emission intensities as well as ratiometric fluorescence.

14.
J Mol Cell Biol ; 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33226078

RESUMO

The coronavirus disease 2019 (COVID-19) remains a global public health emergency. Despite being caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), besides the lung, this infectious disease also has severe implications in cardiovascular system. In this review, we summarize diverse clinical complications of heart and vascular system, as well as the relevant high mortality, in COVID-19 patients. Systemic inflammation and angiotensin-converting enzyme 2-involved signaling networking in SARS-CoV-2 infection and cardiovascular system may contribute to the manifestations of cardiovascular diseases. Therefore, integration of clinical observations and experimental findings can promote our understanding of the underlying mechanisms, which would aid in identifying and treating the cardiovascular injury in patients with COVID-19 appropriately.

15.
Cancer Sci ; 2020 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-33164305

RESUMO

High-mobility group protein A2 (HMGA2) is highly expressed in hepatocellular carcinoma cells and contributes to tumor metastasis and poor patient survival. However, the molecular mechanism through which HMGA2 is transcriptionally regulated in hepatocellular carcinoma (HCC) cells remains largely unclear. Here, we demonstrated that the expression HMGA2 was upregulated in HCC, and the elevated HMGA2 could promote tumor metastasis. Incubation HCC cells with Epidermal Growth Factor (EGF) could promote the expression of HMGA2 mRNA and protein. Mechanistic studies suggested that EGF can phosphorylate p300 at Ser1834 residue through PI3K/Akt signaling pathway in HCC cells. Knockdown of p300 can reverse EGF-induced HMGA2 expression and histone H3-K9 acetylation, while a phosphorylation-mimic p300 S1834D mutant can stimulate HMGA2 expression as well as H3-K9 acetylation in HCC cells. Furthermore, we identified p300-mediated H3-K9 acetylation participates in EGF-induced HMGA2 expression in HCC. In addition, the levels of H3-K9 acetylation positively correlated with the expression levels of HMGA2 in a chemically induced HCC model in rats and human HCC specimens.

16.
Sci Signal ; 13(657)2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33172955

RESUMO

The protein Dickkopf-1 (DKK1) is frequently overexpressed at the transcript level in hepatocellular carcinoma (HCC) and promotes metastatic progression through the induction of ß-catenin, a Wnt signaling effector. We investigated how DKK1 expression is induced in HCC and found that activation of the epidermal growth factor receptor (EGFR) promoted parallel MEK-ERK and PI3K-Akt pathway signaling that converged to epigenetically stimulate DKK1 transcription. In HCC cell lines stimulated with EGF, EGFR-activated ERK phosphorylated the kinase PKM2 at Ser37, which promoted its nuclear translocation. Also in these cells, EGFR-activated Akt phosphorylated the acetyltransferase p300 at Ser1834 Subsequently, PKM2 and p300 mediated the phosphorylation and acetylation, respectively, of histone H3 at the DKK1 promoter, which synergistically enhanced DKK1 transcription. The mechanism was supported with mutational analyses in cells and in a chemically induced HCC model in rats. The findings suggest that dual inhibition of the MEK and PI3K pathways might suppress the expression of DKK1 and, consequently, tumor metastasis in patients with HCC.

17.
Front Microbiol ; 11: 507036, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33178139

RESUMO

The potential infection biology of Plasmodiophora brassicae in resistant hosts and non-hosts is still not completely understood. Clubroot resistance assay on European clubroot differentials (ECD) set revealed that ECD10 (Brassica napus) and ECD4 (Brassica rapa) show a complete resistance to the tested P. brassicae isolate in contrast to highly susceptible hosts Westar (B. napus) and ECD5 (B. rapa). Previously, we used fluorescent probe-based confocal microscopy (FCM) to refine the life cycle of P. brassicae and indicate the important time points during its infection in Arabidopsis. Here, we used FCM to systematically investigate the infection of P. brassicae in two resistant host species ECD10 and ECD4 and two non-host crops wheat and barley at each indicated time points, compared with two susceptible hosts Westar and ECD5. We found that P. brassicae can initiate the primary infection phase and produce uninucleate primary plasmodia in both resistant hosts and non-hosts just like susceptible hosts at 2 days post-inoculation (dpi). Importantly, P. brassicae can develop into zoosporangia and secondary zoospores and release the secondary zoospores from the zoosporangia in resistant hosts at 7 dpi, comparable to susceptible hosts. However, during the secondary infection phase, no secondary plasmodium was detected in the cortical cells of both resistant hosts in contrast to massive secondary plasmodia present in the cortex tissue of two susceptible hosts leading to root swelling at 15 dpi. In both non-host crops, only uninucleate primary plasmodia were observed throughout roots at 7 and 15 dpi. Quantitative PCR based on DNA revealed that the biomass of P. brassicae has no significant increase from 2 dpi in non-host plants and from 7 dpi in resistant host plants, compared to the huge biomass increase in susceptible host plants from 2 to 25 dpi. Our study reveals that the primary infection phase in the root epidermis and the secondary infection phase in the cortex tissue are, respectively, blocked in non-hosts and resistant hosts, contributing to understanding of cellular and molecular mechanisms underlying clubroot non-host and host resistance.

18.
Sci Rep ; 10(1): 20677, 2020 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-33244103

RESUMO

It is known that pig offspring born from pregnant pigs exposed to elevated ambient temperatures during gestation have altered phenotypes, possibly due to placental insufficiency and impaired fetal growth. Therefore, the objective of this study was to quantify the effect of maternal heat exposure during early-mid gestation, when pig placentae grow heavily, on placental and fetal development. Fifteen pregnant pigs were allocated to thermoneutral (TN; 20 °C; n = 7) or cyclic elevated temperature conditions (ET; 28 to 33 °C; n = 8) from d40 to d60 of gestation. Following euthanasia of the pigs on d60, placental and fetal morphometry and biochemistry were measured. Compared to TN fetuses, ET fetuses had increased (P = 0.041) placental weights and a lower (P = 0.013) placental efficiency (fetal/placental weight), although fetal weights were not significantly different. Fetuses from ET pigs had reduced (P = 0.032) M. longissimus fibre number density and a thicker (P = 0.017) placental epithelial layer compared to their TN counterparts. Elevated temperatures decreased (P = 0.026) placental mRNA expression of a glucose transporter (GLUT-3) and increased (P = 0.037) placental IGF-2 mRNA expression. In conclusion, controlled elevated temperatures between d40 to d60 of gestation reduced pig placental efficiency, resulting in compensatory growth of the placentae to maintain fetal development. Placental insufficiency during early-mid gestation may have implications for fetal development, possibly causing a long-term phenotypic change of the progeny.

19.
Animals (Basel) ; 10(11)2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33182569

RESUMO

The backfat of pig carcasses is greater in spring than summer in Australia. The unexplained seasonal variation in carcass backfat creates complications for pig producers in supplying consistent lean carcasses. As a novel explanation, we hypothesised that the increased carcass fatness in spring was due to a greater percentage of born-light progeny from sows that were mated in summer and experienced hot conditions during early gestation. The first part of our experiment compared the birth weight of piglets born to the sows mated in summer (February, the Southern Hemisphere) with those born to sows mated in autumn (May; the Southern Hemisphere), and the second part of the experiment compared the growth performance and carcass fatness of the progeny that were stratified as born-light (0.7-1.1 kg) and born-normal (1.3-1.7 kg) from the sows mated in these two seasons. The results showed that the sows mated in summer experienced hotter conditions during early gestation as evidenced by an increased respiration rate and rectal temperature, compared with those mated in autumn. The sows mated in summer had a greater proportion of piglets that were born ≤1.1 kg (24.2% vs. 15.8%, p < 0.001), lower average piglet birth weight (1.39 kg vs. 1.52 kg, p < 0.001), lower total litter weights (18.9 kg vs. 19.5 kg, p = 0.044) and lower average placental weight (0.26 vs. 0.31 kg, p = 0.011) than those mated in autumn, although litter sizes were similar. Feed intake and growth rate of progeny from 14 weeks of age to slaughter (101 kg live weight) were greater for the born-normal than born-light pigs within the progeny from sows mated in autumn, but there was no difference between the born-light and normal progeny from sows mated in summer, as evidenced by the interaction between piglet birth weight and sow mating season (Both p < 0.05). Only the born-light piglets from the sows mated in summer had a greater backfat thickness and loin fat% than the progeny from the sows mated in autumn, as evidenced by a trend of interaction between piglet birth weight and sow mating season (Both p < 0.10). In conclusion, the increased proportion of born-light piglets (0.7-1.1 kg range) from the sows mated in summer contributed to the increased carcass fatness observed in spring.

20.
ChemSusChem ; 2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33236522

RESUMO

The ordinary intrinsic activity and disordered distribution of metal sites in zero/one-dimensional (0D/1D) single-atom catalysts (SACs) lead to inferior catalytic efficiency and short-term endurance in the oxygen reduction reaction (ORR), which restricts the large-scale application of hydrogen-oxygen fuel cells and metal-air batteries. To improve the activity of SACs, a mild synthesis method was chosen to conjugate 1D Fe SACs with 2D graphene film (Fe SAC@G) that realized a composite structure with well-ordered atomic-Fe coordination configuration. The product exhibits outstanding ORR electrocatalytic efficiency and stability in 0.1 M KOH aqueous solution. DFT-D computational results manifest the intrinsic ORR activity of Fe SAC@G originated from the newly-formed FeN4 -O-FeN4 bridge structure with moderate adsorption ability towards ORR intermediates. These findings provide new ways for designing SACs with high activity and long-term stability.

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