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1.
J Neuroimaging ; 2022 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-35044016

RESUMO

BACKGROUND AND PURPOSE: The effective connectivity of neuronal networks during passive saltatory pneumotactile velocity stimulation to the glabrous hand with different velocities is still unknown. The present study investigated the effectivity connectivity elicited by saltatory pneumotactile velocity arrays placed on the glabrous hand at three velocities (5, 25, and 65 cm/second). METHODS: Dynamic causal modeling (DCM) was used on functional MRI data sampled from 20 neurotypical adults. Five brain regions, including the left primary somatosensory (SI) and motor (M1) cortices, bilateral secondary somatosensory (SII) cortices, and right cerebellar lobule VI, were used to build model space. RESULTS: Three velocities (5, 25, and 65 cm/second) of saltatory pneumotactile stimuli were processed in both serial and parallel modes within the sensorimotor networks. The medium velocity of 25 cm/second modulated forward interhemispheric connection from the contralateral SII to the ipsilateral SII. Pneumotactile stimulation at the medium velocity of 25 cm/second also influenced contralateral M1 through contralateral SI. Finally, the right cerebellar lobule VI was involved in the sensorimotor networks. CONCLUSIONS: Our DCM results suggest the coexistence of both serial and parallel processing for saltatory pneumotactile velocity stimulation. Significant contralateral M1 modulation promotes the prospect that the passive saltatory pneumotactile velocity arrays can be used to design sensorimotor rehabilitation protocols to activate M1. The effective connectivity from the right cerebellar lobule VI to other cortical regions demonstrates the cerebellum's role in the sensorimotor networks through feedforward and feedback neuronal pathways.

2.
Light Sci Appl ; 11(1): 15, 2022 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-35022386

RESUMO

Fibre lasers operating at the mid-IR have attracted enormous interest due to the plethora of applications in defence, security, medicine, and so on. However, no continuous-wave (CW) fibre lasers beyond 4 µm based on rare-earth-doped fibres have been demonstrated thus far. Here, we report efficient mid-IR laser emission from HBr-filled silica hollow-core fibres (HCFs) for the first time. By pumping with a self-developed thulium-doped fibre amplifier seeded by several diode lasers over the range of 1940-1983 nm, narrow linewidth mid-IR emission from 3810 to 4496 nm has been achieved with a maximum laser power of about 500 mW and a slope efficiency of approximately 18%. To the best of our knowledge, the wavelength of 4496 nm with strong absorption in silica-based fibres is the longest emission wavelength from a CW fibre laser, and the span of 686 nm is also the largest tuning range achieved to date for any CW fibre laser. By further reducing the HCF transmission loss, increasing the pump power, improving the coupling efficiency, and optimizing the fibre length together with the pressure, the laser efficiency and output power are expected to increase significantly. This work opens new opportunities for broadly tunable high-power mid-IR fibre lasers, especially beyond 4 µm.

3.
J Colloid Interface Sci ; 606(Pt 1): 248-260, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34390992

RESUMO

Regulating cell behavior and function by surface topography has drawn significant attention in tissue engineering. Herein, a gradient fibrous scaffold comprising anisotropic aligned fibers and isotropic annealed fibers was developed to provide a controllable direction of cell migration, adhesion, and spreading. The electrospun aligned fibers were engraved to create surface gradients with micro-and-nanometer roughness through block copolymer (BCP) self-assembly induced by selective solvent vapor annealing (SVA). The distinct manipulation of cell behavior by annealed fibrous scaffolds with tailored self-assembled nanostructure and welded fibrous microstructure has been illustrated by in situ/ex situ small angle X-ray scattering (SAXS), scanning electron microscopy (SEM), atomic force microscopy (AFM) and in vitro cell culture. Further insights into the effect of integrated gradient fibrous scaffold were gained at the level of protein expression. From the perspective of gradient topology, this region-specific scaffold based on BCP fibers shows the prospect of guiding cell migration, adhesion and spreading and provides a generic method for designing biomaterials for tissue-engineering.


Assuntos
Engenharia Tecidual , Tecidos Suporte , Polímeros , Espalhamento a Baixo Ângulo , Difração de Raios X
4.
J Colloid Interface Sci ; 606(Pt 1): 510-517, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34403860

RESUMO

Gold modified thiol graphene (Au@HS-rGO) was prepared and applied as sensing platform for constructing the electrochemical aptasensor. While gold-palladium modified zirconium metal-organic frameworks (AuPd@UiO-67) nanozyme was employed as signal enhancer for detecting mercury ions (Hg2+) sensitively. Herein, gold nanoparticles (Au NPs) were modified on HS-rGO to form the thin Au@HS-rGO layer. Then the substrate strand (Apt1) was modified on the platform through Au-S bond. The signal strand (Apt2) was further decorated on the platform in the presence of Hg2+. Herein, the Apt2 was labeled with AuPd@UiO-67 nanozyme, which exhibited catalase-like properties to catalyze H2O2, thereby generating the electrical signal. With the concentration of Hg2+ increased, the amount of modified Apt2-AuPd@UiO-67 increased, leading to the rise of current response. Since the current responses were linear with concentration of Hg2+, the detection of Hg2+ can be achieved. Under the optimum conditions, the prepared electrochemical aptasensor exhibited wide linear range from 1.0 nmol/L to 1.0 mmol/L, along with a low detection limit of 0.16 nmol/L. Moreover, the electrochemical aptasensor showed excellent selectivity, reproducibility and stability, together with superior performance in actual water sample analysis. Therefore, this proposed electrochemical aptasensor may have promising applications and provide references for environmental monitoring and management.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Grafite , Mercúrio , Nanopartículas Metálicas , Estruturas Metalorgânicas , Técnicas Eletroquímicas , Ouro , Peróxido de Hidrogênio , Limite de Detecção , Paládio , Reprodutibilidade dos Testes , Compostos de Sulfidrila , Zircônio
5.
Food Chem ; 368: 130853, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34425337

RESUMO

Konjac glucomannan (KGM) is used as an additive to improve the properties of wheat products. The effects of three types of KGM on the rheological properties and microstructure of dough, as well as the performance of steamed bread were investigated in this study. Particularly, dough with KGM displayed new features such as reduced peak viscosity, breakdown and setback. As the viscosity of KGM increased, the stability of the dough structure increased, while the viscosity and fluidity of the dough decreased. More interestingly, the gluten film of dough also increased with increasing substitution level and viscosity of KGM. Consistently, KGM with higher viscosity improved the quality of steamed bread. Generally, three types of KGM have different effects on the rheological characteristics and microstructure of dough, as well as the performance of steamed bread, which provide useful information for the proper application of KGM in wheat-based foods.


Assuntos
Pão , Mananas , Glutens , Reologia , Viscosidade
6.
Chemosphere ; 287(Pt 2): 132183, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34500332

RESUMO

Soil-slurry bioreactor based bioremediation of polycyclic aromatic hydrocarbons (PAHs) contaminated soil was studied through laboratory and pilot-scale trials, in which the degradation mechanism was explored. Indigenous PAH-degrading consortium was firstly screened out and it degraded 80.5% of total PAHs in lab-scale bioreactors. Then a pilot-scale trial lasting 410 days was conducted in two bioreactors of 1.5 m3 to examine the operating parameters and validate the optimum running conditions. During the initial 200 days, the crucial running parameters affecting PAH removal were evaluated and selected. Subsequently, an average PAH removal rate of 93.4% was achieved during 15 consecutive batches (210 days) under the optimum running conditions. The kinetic analysis showed that the reactor under optimum conditions achieved the highest PAH degradation rate of 0.1795 day-1 and the shortest half-life of 3.86 days. Notably, efficient mass transfer of PAHs and high biodegradation capability by bioaugmented consortia in soil-slurry bioreactors were two key mechanisms for appreciable PAH removal performance. Under the optimal operating conditions, the degradation rate of low-molecular-weight (LMW) PAHs was significantly higher than high-molecular-weight (HMW) PAHs; when the mass transfer was limited, there was no significant difference between their degradation behaviors. Both microbial co-metabolism and collaborative metabolism might occur when all PAHs demonstrated low degradation rates. The findings provide insightful guidance on the future assessment and remediation practices of PAH-contaminated sites.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Reatores Biológicos , Cinética , Solo
7.
Psychophysiology ; 59(1): e13942, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34535903

RESUMO

Athletes extract kinematic information to anticipate action outcomes. Here, we examined the influence of linguistic information (experiment 1, 2) and its underlying neural correlates (experiment 2) on anticipatory judgment. Table tennis experts and novices remembered a hand- or leg-related verb or a spatial location while predicting the trajectory of a ball in a video occluded at the moment of the serve. Experiment 1 showed that predictions by experts were more accurate than novices, but experts' accuracy significantly decreased when hand-related words versus spatial locations were memorized. For nonoccluded videos with ball trajectories congruent or incongruent with server actions in experiment 2, remembering hand-related verbs shared cognitive resources with action anticipation only in experts, with heightened processing load (increased P3 amplitude) and more efficient conflict monitoring (decreased N2 amplitude) versus leg-related verbs. Thus, action anticipation required updating of motor representations facilitated by motor expertize but was also affected by effector-specific semantic representations of actions, suggesting a link from language to motor systems.

8.
Behav Brain Res ; 417: 113594, 2022 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-34560129

RESUMO

In this study, we tested the hypothesis that the Piezo1/Ca2+/calpain pathway of the basal forebrain (BF) modulates impaired fear conditioning caused by sleep deprivation. Adult male Wistar rats were subjected to 6 h of total sleep deprivation using the gentle handling protocol. Step-down inhibitory avoidance tests revealed that sleep deprivation induced substantial short- and long-term fear memory impairment in rats, which was accompanied by increased Piezo1 protein expression (P < 0.01) and increased cleavage of full-length tropomyocin receptor kinase B (TrkB-FL) (P < 0.01) in the BF area. Microinjection of the Piezo1 activator Yoda1 into the BF mimicked these sleep deprivation-induced phenomena; TrkB-FL cleavage was increased (P < 0.01) and short- and long-term fear memory was impaired (both P < 0.01) by Yoda1. Inhibition of Piezo1 by GsMTx4 in the BF area reduced TrkB-FL degradation (P < 0.01) and partially reversed short- and long-term fear memory impairments in sleep-deprived rats (both P < 0.01). Inhibition of calpain activation, downstream of Piezo1 signaling, also improved short- and long-term fear memory impairments (P = 0.038, P = 0.011) and reduced TrkB degradation (P < 0.01) in sleep-deprived rats. Moreover, sleep deprivation induced a lower pain threshold than the rest control, which was partly reversed by microinjection of GsMTx4 or PD151746. Neither sleep deprivation nor the abovementioned drugs affected locomotion and sedation. Taken together, these results indicate that BF Piezo1/Ca2+/calpain signaling plays a role in sleep deprivation-induced TrkB signaling disruption and fear memory impairments in rats.

10.
Biochem Biophys Res Commun ; 589: 165-172, 2022 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-34922198

RESUMO

Low serum bicarbonate is closely related to type 2 diabetes mellitus. However, the precise role of bicarbonate on glucose homeostasis and insulin secretion remains unknown. In this study, we investigated the effects of bicarbonate concentration on pancreatic ß-cells. It was observed that the high bicarbonate concentration of the cell culture medium significantly increased the glucose-induced insulin secretion (GSIS) levels in mouse islets, MIN6, and the INS-1E ß cells. MIN6 cells presented an impaired GSIS; the cells produced a lower bicarbonate concentration when co-cultured with Capan-1 than when with CFPAC-1. NBCe1, a major bicarbonate transporter was observed to block the increasing insulin secretions, which were promoted by a high concentration of bicarbonate. In addition, higher extracellular bicarbonate concentration significantly increased the intracellular cAMP level, pHi, and calcium concentration with a 16.7 mM of glucose stimulation. Further study demonstrated that a low concentration of extracellular bicarbonate significantly impaired the functioning of pancreatic ß cells by reducing coupling Ca2+ influx, whose process may be modulated by NBCe1. Taken together, our results conclude that bicarbonate may serve as a novel target in diabetes prevention-related research.

11.
Front Oncol ; 11: 746750, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34868946

RESUMO

Objectives: This study was conducted in order to design and develop a framework utilizing deep learning (DL) to differentiate papillary renal cell carcinoma (PRCC) from chromophobe renal cell carcinoma (ChRCC) using convolutional neural networks (CNNs) on a small set of computed tomography (CT) images and provide a feasible method that can be applied to light devices. Methods: Training and validation datasets were established based on radiological, clinical, and pathological data exported from the radiology, urology, and pathology departments. As the gold standard, reports were reviewed to determine the pathological subtype. Six CNN-based models were trained and validated to differentiate the two subtypes. A special test dataset generated with six new cases and four cases from The Cancer Imaging Archive (TCIA) was applied to validate the efficiency of the best model and of the manual processing by abdominal radiologists. Objective evaluation indexes [accuracy, sensitivity, specificity, receiver operating characteristic (ROC) curve, and area under the curve (AUC)] were calculated to assess model performance. Results: The CT image sequences of 70 patients were segmented and validated by two experienced abdominal radiologists. The best model achieved 96.8640% accuracy (99.3794% sensitivity and 94.0271% specificity) in the validation set and 100% (case accuracy) and 93.3333% (image accuracy) in the test set. The manual classification achieved 85% accuracy (100% sensitivity and 70% specificity) in the test set. Conclusions: This framework demonstrates that DL models could help reliably predict the subtypes of PRCC and ChRCC.

12.
Nanoscale ; 2021 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-34874030

RESUMO

In the field of catalysis, the design and construction of nanomaterials is an efficient way to optimize the catalytic activity of catalysts. This study presents the synthesis of PtCu tripod nanocrystals with branching structures and high purity prepared using a simple hydrothermal method. The dendritic PtCu triangular nanocrystals were successfully synthesized by regulating the amount of I- ions to achieve different degrees of branching on PtCu nanocrystals, and the process was systematically studied and analyzed. Meanwhile, dumbbell nanocrystals of PtCu were successfully synthesized through slight adjustments to synthesis conditions. In electrochemical tests, the obtained dendritic PtCu triangular nanocrystals exhibited prominent electrocatalytic activity and long-term stability for ethylene glycol, methanol, and ethanol oxidation reactions due to the unique nanostructures as well as alloyed virtue, and were much better than commercial Pt/C. In addition, this study provides a general strategy for designing novel branched Pt-based nanomaterials with high electrocatalytic performance.

13.
Biosci Trends ; 2021 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-34880159

RESUMO

We explored the prognostic value of preoperative CA19-9 in α-fetoprotein (AFP)-positive and -negative HCC with hepatitis B virus (HBV) background (HBV-HCC), and explored the underlying mechanism. Recurrence-free survival (RFS) and overall survival (OS) were assessed in HBV-HCC patients who underwent curative resection (Cohort 1). Immunohistochemical staining of CA19-9 in HCC and liver parenchyma were quantified in another cohort of 216 patients with resected HCC (Cohort 2). Immunohistochemical staining of CA19-9 and serum CA19-9 level was also compared between patients with HCC and intrahepatic cholangiocarcinoma (ICC) (Cohort 3). In Cohort 1, CA19-9 ≥ 39 U/mL was an independent risk factor for RFS (HR = 1.507, 95% CI = 1.087-2.091, p = 0.014) and OS (HR = 1.646, 95% CI = 1.146-2.366, p = 0.007). CA19-9 ≥ 39 U/mL was also associated with significantly higher incidence of macrovascular invasion (MaVI) compared with CA19-9 < 39 U/mL (23.0% vs. 7.2%, p = 0.002), and elevated aminotransferase and aspartate aminotransferase to platelet ratio index (APRI), and lower albumin. Immunohistochemical staining of CA19-9 revealed that CA19-9 expression was found exclusively in the background liver but not in HCC tumor cells. In contrast, tumor tissue was the main source of CA19-9 in ICC patients. CA19-9 ≥ 39 U/mL was associated with worse OS and RFS in both AFP-positive and negative HCC patients. CA19-9 indicated more severe inflammation and cirrhosis in the liver of HCC patients.

14.
Front Psychol ; 12: 773134, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34858298

RESUMO

Background: Most studies on mental health problems caused by COVID-19 crisis in children were limited to the period of home quarantine. It remained unclear what adverse impact of the psychosocial stressors caused by school reopening, as well as the transitions in daily activities and social interactions had on mental health in children. Methods: A total of 6400 students in primary schools were enrolled in a cross-sectional study conducted in East China, between June 26 and July 6, 2020, when schools reopened. Children's mental health status was assessed by the parent version of Strengths and Difficulties Questionnaire (SDQ). Ultimately, data on a total of 6017 children with completed information on mental health, psychosocial stressors, daily activities, and social interactions were eligible for analysis. The associations of mental health with psychosocial stressors, daily activities, and social interactions were determined by ordinal logistic regression models. Stratified analyses were conducted according to grade, gender, school level, area, and caregiver-child relationship to further observe the effects of stressors on mental status. Results: The prevalence of borderline, moderately abnormal, and prominently abnormal scores were 7.16, 3.34, and 1.96% for total difficulties, and 13.83, 13.45, and 17.85% for prosocial behavior, respectively. Children with psychological stressors had a significantly higher risk of being in a worse category of mental health status, with the maximum adjusted OR of 7.90 (95% CI 3.33-18.75) in those definitely afraid of inadaptation to study and life styles. Time used in home work and computer games was positively related to mental health problems, while physical exercises and frequency of communication with others was negatively related. The effects of psychological stressors on total difficulties were more evident in middle-high grade students (OR = 7.52, 95% CI 4.16-8.61), boys (OR = 6.95, 95% CI 4.83-8.55), those who lived in Taizhou (OR = 7.62, 95% CI 4.72-8.61) and with poor caregiver-child relationship (OR = 7.79, 95% CI 2.26-8.65). Conclusion: Emotional and behavioral difficulties, especially less prosocial behavior, were prevalent in primary school children after schools reopened. The Chinese government, communities, schools, and families need to provide more effective support for students' transition back into the school building and address emotional and behavioral problems for children with difficulties.

15.
Br J Nutr ; : 1-26, 2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34863319

RESUMO

Hyperinsulinemia and insulin resistance have been proposed to be associated with mortality risk, and diet can modulate insulin response. However, whether dietary patterns with high insulinemic potential are associated with mortality remains unknown. We prospectively examined the associations between hyperinsulinemic diets and the risk of total and cause-specific mortality in a large nationally representative population. Dietary factors were assessed by 24-hour recalls. Two empirical dietary indices for hyperinsulinemia (EDIH) and insulin resistance (EDIR) were developed to identify food groups most predictive of biomarkers for hyperinsulinemia (C-peptide and insulin) and insulin resistance (homeostatic model assessment for insulin resistance), respectively. Deaths from date of the first dietary interview until December 31, 2015 were identified by the National Death Index. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox regression models. During a median follow-up of 7.8 years, 4,904 deaths were documented among 40,074 participants. For EDIH, the multivariable-adjusted HRs (comparing extreme quintiles) were 1.20 (95% CI: 1.09-1.32, P-trend<0.001) for overall mortality, and 1.41 (95% CI: 1.15-1.74, P-trend=0.002) for cardiovascular disease (CVD) mortality. Similar associations were observed for EDIR with HRs of 1.18 (95% CI: 1.07-1.29, P-trend<0.001) for total and 1.35 (95% CI: 1.09-1.67, P-trend=0.005) for CVD mortality. After further adjustments for body mass index and diabetes, these positive associations were somewhat attenuated, but most remained statistically significant. Our findings suggested that diets with higher insulinemic potential are associated with increased risk of overall and CVD-specific mortality. Strategies to avoid hyperinsulinemic dietary patterns may potentially promote health and longevity.

16.
Free Radic Biol Med ; 178: 111-124, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34863875

RESUMO

Inflammation has recently emerged as an important contributor for cardiovascular disease development and participates pivotally in the development of neointimal hyperplasia and abdominal aortic aneurysms (AAA) formation. Kv7.4/KCNQ4, a K+ channel, is one of the important regulators of vascular function but its role in vascular inflammation is unexplored. Here, we showed that the expression of Kv7.4 channel was elevated in the neointima and AAA tissues from mice and humans. Genetic deletion or pharmacological inhibition of Kv7.4 channel in mice alleviated neointimal hyperplasia and AAA formation via downregulation of a set of vascular inflammation-related genes, matrix metalloproteinases (MMP) 2/9, and intercellular adhesion molecule (ICAM-1). Furthermore, genetic deletion or inhibition of Kv7.4 channel suppressed the activation of tumor necrosis factor receptor 1 (TNFR1)-nuclear factor (NF)-κB signaling pathway via blockade of interaction between TNFR1 and TNFR1-associated death domain protein (TRADD) in vascular smooth muscle cells (VSMCs). Knockdown of Kv7.4 in vivo identified VSMC-expressed Kv7.4 as a major factor in vascular inflammation. Collectively, our findings suggest that Kv7.4 channel aggravates vascular inflammatory response, which promotes the neointimal hyperplasia and AAA formation. Inhibition of Kv7.4 channel may be a novel therapeutic strategy for vascular inflammatory diseases.

17.
Curr Alzheimer Res ; 18(13): 1041-1056, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34915837

RESUMO

BACKGROUND: Background: Alzheimer's disease (AD) is the most common cause of dementia. As a heterogenous disease, there are several clinically and pathobiological defined subtypes with different molecular signatures. Neuroinflammation contributed to AD pathogenesis, however, the roles it played in the heterogeneity of AD was unclear. OBJECTIVE: We aimed to illustrate the roles neuroinflammation played in the heterogeneity of AD. METHOD: An integrative network analysis based on transcriptomics, miRNOmics, and proteomics was performed to illustrate the heterogeneous characters of AD. Combined-functional-networks and hypothesis- network were constructed and analyzed to explore the roles neuroinflammation played in AD heterogeneity. RESULTS: Astrocytes, microglia, 'M2 macrophage-Neuron', and 'Microglia- Neuron' were shown to be enriched in neuroinflammation related functional terms in a cell- and spatial-specific way. The microglia and neurons could interact with each other in three different ways including indirect interactions via intermediate cells, indirect interactions via soluble factors, and direct interactions established localized and functionally distinct signaling, all of which were used to control different biological processes. The combined network analyses exhibited the key roles neuroinflammation plays in the 'AD hypothesis network'. CONCLUSION: The AD heterogeneity may be caused by the heterogeneous cells involved in neuroinflammation and the crosstalks between spatial-specific molecular signatures.

18.
Neuroimage Clin ; 33: 102930, 2021 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-34959050

RESUMO

The purpose of this study was to reveal the patterns of reorganization of rich club organization in brain functional networks in dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). The study found that the rich club node shifts from sensory/somatomotor network to fronto-parietal network in DLB. For AD, the rich club nodes switch between the temporal lobe with obvious structural atrophy and the frontal lobe, parietal lobe and cerebellum with relatively preserved structure and function. In addition, compared with healthy controls, rich club connectivity was enhanced in the DLB and AD groups. The connection strength of DLB patients was related to cognitive assessment. In conclusion, we revealed the different functional reorganization patterns of DLB and AD. The conversion and redistribution of rich club members may play a causal role in disease-specific outcomes. It may be used as a potential biomarker to provide more accurate prevention and treatment strategies.

19.
Animals (Basel) ; 11(12)2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34944154

RESUMO

The high-altitude ecosystem of the Tibetan Plateau in China is a biodiversity hotspot that provides unique habitats for endemic and relict species along an altitudinal gradient at the eastern edge. Acquiring biodiversity information in this area, where the average altitude is over 4000 m, has been difficult but has been aided by recent developments in non-invasive technology, including infrared-triggered camera trapping. We used camera trapping to acquire a substantial number of photographic wildlife records in Wolong National Nature Reserve, Sichuan, China, from 2013 to 2016. We collected information of the habitat surrounding the observation sites, resulting in a dataset covering 37 species and 12 environmental factors. We performed a multivariate statistical analysis to discern the dominant environmental factors and cluster the mammals and birds of the ecosystem in order to examine environmental factors contributing to the species' relative abundance. Species were generalized into three main types, i.e., cold-resistant, phyllophilic, and thermophilic, according to the identified key environmental drivers (i.e., temperature and vegetation) for their abundances. The mammal species with the highest relative abundance were bharal (Pseudois nayaur), Moupin pika (Ochotona thibetana), and Himalayan marmot (Marmota himalayana). The bird species with highest relative abundance were snow partridge (Lerwa lerwa), plain mountain finch (Leucosticte nemoricola), Chinese monal (Lophophorus lhuysii), and alpine accentor (Prunella collaris).

20.
Biotechnol Biofuels ; 14(1): 241, 2021 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-34920742

RESUMO

BACKGROUND: As the second most abundant polysaccharide in nature, hemicellulose can be degraded to xylose as the feedstock for bioconversion to fuels and chemicals. To enhance xylose conversion, the engineered Saccharomyces cerevisiae with xylose metabolic pathway is usually adapted with xylose as the carbon source in the laboratory. However, the mechanism under the adaptation phenomena of the engineered strain is still unclear. RESULTS: In this study, xylose-utilizing S. cerevisiae was constructed and used for the adaptation study. It was found that xylose consumption rate increased 1.24-fold in the second incubation of the yYST12 strain in synthetic complete-xylose medium compared with the first incubation. The study figured out that it was observed at the single-cell level that the stagnation time for xylose utilization was reduced after adaptation with xylose medium in the microfluidic device. Such transient memory of xylose metabolism after adaptation with xylose medium, named "xylose consumption memory", was observed in the strains with both xylose isomerase pathway and xylose reductase and xylitol dehydrogenase pathways. In further, the proteomic acetylation of the strains before and after adaptation was investigated, and it was revealed that H4K5 was one of the most differential acetylation sites related to xylose consumption memory of engineered S. cerevisiae. We tested 8 genes encoding acetylase or deacetylase, and it was found that the knockout of the GCN5 and HPA2 encoding acetylases enhanced the xylose consumption memory. CONCLUSIONS: The behavior of xylose consumption memory in engineered S. cerevisiae can be successfully induced with xylose in the adaptation. H4K5Ac and two genes of GCN5 and HPA2 are related to xylose consumption memory of engineered S. cerevisiae during adaptation. This study provides valuable insights into the xylose adaptation of engineered S. cerevisiae.

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