To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
The study was conducted to determine the effects of three dietary Se sources, such as sodium-selenite (S-S), seleno-yeast (S-Y) and seleno-methionine (S-M), on Se concentration, glutathione peroxidase (GPX) and TXNRD activities, and mRNA expression of fifteen representative selenoproteins, and protein expression of four endoplasmic reticulum-resided selenoproteins in a wide range of tissues of yellow catfish. Compared with S-S and S-M groups, dietary S-Y significantly decreased growth performance and feed utilisation of yellow catfish. Dietary Se sources significantly influenced Se contents in the spleen, dorsal muscle and the kidney, GPX activities in spleen, kidney, intestine, muscle and mesenteric fat, and TXNRD activities in the heart, intestine and mesenteric fat. Among ten tested tissues, dietary Se sources influenced mRNA expression of GPX4 and SELENOK in three tissues; GPX3, SELENOS and TXNRD2 in four tissues; SELENOF, SELENON and DIO2 in five tissues; SELENOM, GPX1/2 and TXNRD3 in six tissues; SELENOW in seven tissue and SELENOP and SELENOT in eight tissues. Based on these observations above, S-S and S-M seem to be suitable Se sources for improving growth performance and feed utilisation of yellow catfish. Dietary Se sources differentially influence the expression of selenoproteins in various tissues of yellow catfish. For the first time, we determined the expression of selenoproteins in fish in responses to dietary Se sources, which contributes to a better understanding of the functions and regulatory mechanisms of selenoporteins.
Toxoplasma gondii can infect almost all warm-blooded vertebrates with pathogensis being largely influenced by the host immune status. As important epidemiological hosts, rodents are globally distributed and are also commonly found infected with haemoflagellates, such as those in the genus Trypanosoma. We here address whether and how co-infection with trypanosomes can influence T. gondii infection in laboratory models. Rats of five strains, co-infected with T. lewisi and mice of four strains, co-infected with T. musculi, were found to be more or less susceptible to T. gondii infection, respectively, with corresponding increased or decreased brain cyst burdens. Downregulation of iNOS expression and decreased NO production or reverse were observed in the peritoneal macrophages of rats or mice, infected with trypanosomes, respectively. Trypanosoma lewisi and T. musculi can modulate host immune responses, either by enhancement or suppression and influence the outcome of Toxoplasma infection.
In present study, we explored the effects and the underlying mechanisms of phospholipase C (PLC) mediating glucose-induced changes in intestinal glucose transport and lipid metabolism by using U-73122 (a PLC inhibitor). We found that glucose incubation activated the PLC signal and U-73122 pre-incubation alleviated the glucose-induced increase in plcb2, plce1 and plcg1 mRNA expression. Meanwhile, U-73122 pre-treatment blunted the glucose-induced increase in sodium/glucose co-transporters 1/2 mRNA and protein expressions. U-73122 pre-treatment alleviated the glucose-induced increase in TAG content, BODIPY 493/503 fluorescence intensity, lipogenic enzymes (glucose 6-phospate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), malic enzyme and fatty acid synthase (FAS)) activity and the mRNA expressions of lipogenic genes and related transcription factors (6pgd, g6pd, fas, acca, srebp1 and carbohydrate response element-binding protein (chrebp)) in intestinal epithelial cells of yellow catfish. Further research found that U-73122 pre-incubation mitigated the glucose-induced increase in the ChREBP protein expression and the acetylation level of ChREBP in HEK293T cells. Taken together, these data demonstrated that the PLC played a major role in the glucose-induced changes of glucose transport and lipid metabolism and provide a new perspective for revealing the molecular mechanism of glucose-induced changes of intestinal glucose absorption, lipid deposition and metabolism.
Since December 2019, China has experienced a widespread outbreak of COVID-19. However, at the early stage of outbreak, investigations revealed a variety of patterns resulting in the transmission of COVID-19. Thus, it is essential to understand the transmission types and the potential for sustained human-to-human transmission. Moreover, the information regarding the characteristics of transmission helps in coordinating the current screening programme, and controlling and containing measures, and also, helps in deciding the appropriate quarantine duration. Thus, this investigation reports an outbreak of COVID-19 in a family residing in Wenzhou, Zhejiang, China during the month of January−February 2020.
For the guarantee of the long-distance transport of the bunches of China Initiative Accelerator Driven System (CIADS), a new scheme is proposed that extra magnetic field is used in the accelerator-target coupling section before the windowless target to minimize the self-modulation (SM) mechanism. Particle-in-cell simulations are carried out to study the influence of the solenoidal magnetic field on the self-modulation mechanism when long proton bunches move in the background plasmas. The long proton bunches used in the simulations are similar to these in the linear accelerator of CIADS. It is found that the presence of the solenoidal magnetic field will significantly inhibit the self-modulation process. For the strong magnetic field, the longitudinal separation and transverse focusing of the long bunches disappear. We attribute these phenomena to the reason that the strong solenoidal magnetic field restricts the transverse movement of plasma electrons. Thus, there are not enough electrons around the bunch to compensate the space charge effect. Moreover, without transverse current, the longitudinal pinched effect disappears, and the long bunch can not be separated into small pulses anymore.
Primary liver cancer is the third leading cause of cancer-related death worldwide. Most patients are diagnosed at late stages with poor prognosis; thus, identification of modifiable risk factors for primary prevention of liver cancer is urgently needed. The well-established risk factors of liver cancer include chronic infection with hepatitis B virus (HBV) or hepatitis C virus (HCV), heavy alcohol consumption, metabolic diseases such as obesity and diabetes, and aflatoxin exposure. However, a large proportion of cancer cases worldwide cannot be explained by current known risk factors. Dietary factors have been suspected as important, but dietary aetiology of liver cancer remains poorly understood. In this review, we summarised and evaluated the observational studies of diet including single nutrients, food and food groups, as well as dietary patterns with the risk of developing liver cancer. Although there are large knowledge gaps between diet and liver cancer risk, current epidemiological evidence supports an important role of diet in liver cancer development. For example, exposure to aflatoxin, heavy alcohol drinking and possibly dairy product (not including yogurt) intake increase, while intake of coffee, fish and tea, light-to-moderate alcohol drinking and several healthy dietary patterns (e.g. Alternative Healthy Eating Index) may decrease liver cancer risk. Future studies with large sample size and accurate diet measurement are warranted and need to consider issues such as the possible aetiological heterogeneity between liver cancer subtypes, the influence of chronic HBV or HCV infection, the high-risk populations (e.g. cirrhosis) and a potential interplay with host gut microbiota or genetic variations.
In this paper, we innovatively conduct a Porro prism-based beam pointing stability promotion technique research and realize a high-performance rod-type photonic crystal fiber-based chirped pulse amplification (CPA) system, mainly including a frequency-reduced all-fiber pre-amplification stage, photonic crystal rod-based main amplification stage, and 1600 lines/mm transmission grating-pair compressor. Laser output with average power of 50 W, repetition rates of 500 kHz, pulse energy of 100 μJ, pulse duration of 830 fs, beam quality of M2<1.3, power fluctuation of 0.55% root mean square, and beam pointing drift of 19 μrad/°C over 8 h is realized. The high-performance laser system has an enormous application potential in fundamental research and precision manufacturing fields.
In the laser plasma interaction of quantum electrodynamics (QED)-dominated regime, γ-rays are generated due to synchrotron radiation from high-energy electrons traveling in a strong background electromagnetic field. With the aid of 2D particle-in-cell code including QED physics, we investigate the preplasma effect on the γ-ray generation during the interaction between an ultraintense laser pulse and solid targets. We found that with the increasing preplasma scale length, the γ-ray emission is enhanced significantly and finally reaches a steady state. Meanwhile, the γ-ray beam becomes collimated. This shows that, in some cases, the preplasmas will be piled up acting as a plasma mirror in the underdense preplasma region, where the γ-rays are produced by the collision between the forward electrons and the reflected laser fields from the piled plasma. The piled plasma plays the same role as the usual reflection mirror made from a solid target. Thus, a single solid target with proper scale length preplasma can serve as a manufactural and robust γ-ray source.
The microbiota–gut–brain axis, especially the microbial tryptophan (Trp) biosynthesis and metabolism pathway (MiTBamp), may play a critical role in the pathogenesis of major depressive disorder (MDD). However, studies on the MiTBamp in MDD are lacking. The aim of the present study was to analyze the gut microbiota composition and the MiTBamp in MDD patients.
We performed shotgun metagenomic sequencing of stool samples from 26 MDD patients and 29 healthy controls (HCs). In addition to the microbiota community and the MiTBamp analyses, we also built a classification based on the Random Forests (RF) and Boruta algorithm to identify the gut microbiota as biomarkers for MDD.
The Bacteroidetes abundance was strongly reduced whereas that of Actinobacteria was significantly increased in the MDD patients compared with the abundance in the HCs. Most noteworthy, the MDD patients had increased levels of Bifidobacterium, which is commonly used as a probiotic. Four Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologies (KOs) (K01817, K11358, K01626, K01667) abundances in the MiTBamp were significantly lower in the MDD group. Furthermore, we found a negative correlation between the K01626 abundance and the HAMD scores in the MDD group. Finally, RF classification at the genus level can achieve an area under the receiver operating characteristic curve of 0.890.
The present findings enabled a better understanding of the changes in gut microbiota and the related Trp pathway in MDD. Alterations of the gut microbiota may have the potential as biomarkers for distinguishing MDD patients form HCs.
The pathophysiology of obsessive-compulsive disorder (OCD) remains unclear despite extensive neuroimaging work on the disorder. Exposure to medication and comorbid mental disorders can confound the results of OCD studies. The goal of this study was to explore differences in brain functional connectivity (FC) within the cortico-striato-thalamo-cortical (CSTC) loop of drug-naïve and drug-free OCD patients and healthy controls (HCs).
A total of 29 drug-naïve OCD patients, 22 drug-free OCD patients, and 25 HCs matched on age, gender and education level underwent functional magnetic resonance imaging scanning at resting state. Seed-based connectivity analyses were conducted among the three groups. The Yale Brown Obsessive Compulsive Scale and clinical inventories were used to assess the clinical symptoms.
Compared with HCs, the drug-naïve OCD patients had reduced FC within the limbic CSTC loop. In the drug-naïve OCD participants, we also found hyperconnectivity between the supplementary motor area and ventral and dorsal putamen (p < 0.05, corrected for multiple comparisons).
Exposure to antidepressants such as selective serotonin reuptake inhibitors may affect the function of some brain regions. Future longitudinal studies could help to reveal the pharmacotherapeutic mechanisms in these loops.
Disturbances in lipid metabolism are at the core of several health issues facing modern society, including fatty liver and obesity. The sterol regulatory element-binding protein 1 (SREBP-1) is one important transcription factor regulating lipid metabolism, but the relevant mechanism still remains unknown. The present study determined the transcriptional regulation of SREBP-1 and its target genes (including acetyl-CoA carboxylase α (accα), fatty acid synthase (fas) and stearoyl-CoA desaturase 1 (scd1)) in a freshwater teleost, grass carp Ctenopharyngodon idella. We cloned and characterised the 1988 bp, 2043 bp, 1632 bp and 1889 bp sequences of srebp-1, accα, scd1 and fas promoters, respectively. A cluster of putative binding sites of transcription factors, such as specific protein, yin yang 1, nuclear factor Y, sterol response elements (SRE) and enhancer box (E-box) element, were predicted on their promoter regions. Overexpression of nSREBP-1 reduced srebp-1 promoter activity, increased scd1 and fas promoter activity but did not influence accα promoter activity. The site-mutation and electrophoretic mobility shift assay analysis indicated that srebp-1, fas and scd1 promoters, but not accα promoter, possessed SRE. In Ctenopharyngodon idella kidney (CIK) cells of grass carp, nSREBP-1 overexpression significantly reduced srebp-1 mRNA expression and up-regulated miR-29 mRNA expression. The 3′UTR of srebp-1 possessed the potential miR-29 binding site and miR-29 up-regulated the luciferase activity of srebp-1 3′UTR and srebp-1 mRNA expression, implying a self-activating loop of SREBP-1 and miR-29 in grass carp. Based on the above-mentioned results, we found two novel transcriptional mechanisms for SREBP-1 in grass carp: (1) the auto-regulation sited on the SREBP-1 promoter regions was suppressive and (2) there was a self-activating loop of SREBP-1 and miR-29.
The two-phase flow pattern of a flow mixing nozzle plays an important role in jet breakup and atomization. However, the flow pattern of this nozzle and its transformation characteristics are still unclear. A diesel-air injection simulation model of a flow mixing nozzle is established. Then the two-phase flow pattern and transformation characteristics of the flow mixing nozzle is studied using a numerical simulation method. The effect of the air-diesel velocity ratio, ratio of the distance between the tube orifice and nozzle hole and the tube diameter (H/D), and the diesel inlet velocity was studied in terms of the jet breakup diameter (jet diameter at the breakup position) and jet breakup length (length of the diesel jet from the breakup position to the nozzle outlet). The results show that the jet breakup diameter decreases with the decrease in H/D or the increase in the air-diesel velocity ratio and diesel inlet velocity. The jet breakup length increases first and then decreases with the increase in H/D and air-diesel velocity ratio; the trend of the diesel inlet velocity is complicated. In addition, a change in the working conditions also causes some morphological changes that cannot be quantitatively analyzed in the diesel-air flow pattern. The transition characteristics of the flow pattern are analyzed, and it is found that the main reason for the change in the flow pattern is the change in the inertial force of the air, surface tension force, and viscous force of diesel (non-dimensional Reynolds number and Weber number describe the transition characteristics in this paper). The surface tension force of diesel decreases and the viscous force of diesel and inertial force of air increase when the air-diesel velocity ratio increases or H/D decreases. However, the effects of the diesel surface tension force and viscous force effect are much smaller than that of the air inertial force, which changes the diesel-air flow pattern from a drop pattern to a vibration jet pattern, broken jet pattern, and then a chaotic jet pattern.
Subcutaneous immunotherapy is an effective and safe treatment for allergic rhinitis and allergic asthma. Different symptom scores are used to evaluate the efficacy of subcutaneous immunotherapy in clinical trials.
A total of 58 allergic rhinitis patients sensitised to house dust mites, with or without mild asthma, were included. Symptom score, medication score, visual analogue scale score and quality of life were assessed before and after 6, 12 and 24 months of subcutaneous immunotherapy.
After two years of subcutaneous immunotherapy, asthma symptom scores nearly reached zero, whereas the scores remained higher for nasal symptoms. The changes in asthma symptom scores were markedly different (p < 0.05) and occurred faster than the changes in nasal symptom scores when compared between monosensitised and polysensitised groups. Significant reductions in visual analogue scale score and medication score were demonstrated after subcutaneous immunotherapy.
Two-year subcutaneous immunotherapy with house dust mite vaccine is an effective treatment for both monosensitised and polysensitised allergic patients. The changes in asthma symptom scores were markedly different and occurred quicker than the changes in nasal symptom scores in Chinese house dust mite allergic patients.
Kaolinite can be used for many applications, including the underground storage of gases. Density functional theory was employed to investigate the adsorption of hydrogen molecules on the kaolinite (001) surface. The coverage dependence of the adsorption sites and energetics was studied systematically for a wide range of coverage, Θ (from 1/16 to 1 monolayer). The three-fold hollow site is the most stable, followed by the bridge, top-z and top sites. The adsorption energy of H2 decreased with increasing coverage, thus indicating the lower stability of surface adsorption due to the repulsion of neighbouring H2 molecules. The coverage has obvious effects on hydrogen adsorption. Other properties of the H2/kaolinite (001) system, including the lattice relaxation and changes of electronic density of states, were also studied and are discussed in detail.
The role of the cerebellum in obsessive-compulsive disorder (OCD) has drawn increasing attention. However, the functional connectivity between the cerebellum and the cerebral cortex has not been investigated in OCD, nor has the relationship between such functional connectivity and clinical symptoms.
A total of 27 patients with OCD and 21 healthy controls (HCs) matched on age, sex and education underwent magnetic resonance imaging (MRI). Seed-based connectivity analyses were performed to examine differences in cerebellar-cerebral connectivity in patients with OCD compared with HCs. Associations between functional connectivity and clinical features in OCD were analyzed.
Compared with HCs, OCD patients showed significantly decreased cerebellar-cerebral functional connectivity in executive control and emotion processing networks. Within the OCD group, decreased functional connectivity in an executive network spanning the right cerebellar Crus I and the inferior parietal lobule was positively correlated with symptom severity, and decreased connectivity in an emotion processing network spanning the left cerebellar lobule VI and the lingual gyrus was negatively correlated with illness duration.
Altered functional connectivity between the cerebellum and cerebral networks involved in cognitive-affective processing in patients with OCD provides further evidence for the involvement of the cerebellum in the pathophysiology of OCD, and is consistent with impairment in executive control and emotion regulation in this condition.
The effect of Si on Fe-rich intermetallic formation and the mechanical properties of the heat-treated squeeze cast Al–5.0Cu–0.6Mn–0.7Fe alloy was investigated. Our results show that increasing the Si content promotes the formation of Al15(FeMn)3(SiCu)2 (α-Fe) and varies the morphology of T (Al20Cu3Mn2), where the size decreases and the amount increases. The major reason is that Si promotes heterogeneous nucleation of the intermetallics leading to finer precipitates. Si addition significantly enhances the ultimate tensile strength and yield strength of the alloys. The strengthening effect is mainly owing to the dispersoid strengthening by increasing the volume fraction of the T phase and less harmful α-Fe with a compact structure, which makes it more difficult for the cracks to initiate and propagate during tensile test. The squeeze cast Al–5.0Cu–0.6Mn–0.7Fe alloy with 1.1% Si shows significantly improved mechanical properties than the alloy without Si addition, which has a tensile strength of 386 MPa, yield strength of 280 MPa, and elongation of 8.6%.
Some convergence bounds of the minimal residual (MINRES) method are studied when the method is applied for solving Hermitian indefinite linear systems. The matrices of these linear systems are supposed to have some properties so that their spectra are all clustered around ±1. New convergence bounds depending on the spectrum of the coefficient matrix are presented. Some numerical experiments are shown to demonstrate our theoretical results.
To investigate lung function in Chinese patients suffering from chronic rhinosinusitis with nasal polyps and examine its association with histopathological features.
The lung function of 99 patients with nasal polyps was measured. Haematoxylin and eosin and immunohistochemistry staining were performed to evaluate any inflammatory cells and epithelial tissue remodelling.
Predicted maximal expiratory flow rate at 25 per cent vital capacity was reduced (p < 0.05) in epithelial hyperplasia, and predicted maximal expiratory flow rate at 50 per cent vital capacity was reduced (p < 0.05) in goblet cell hyperplasia. Both peripheral blood eosinophilia and tissue eosinophilia nasal polyps manifested significantly reduced: forced expiratory volume in 1 second/forced vital capacity ratio, predicted maximal expiratory flow rate at 25, 50 and 75 per cent of vital capacity, and predicted maximal mid-expiratory flow. Peripheral blood eosinophils were negatively correlated with predicted maximal expiratory flow rate at 25 and 50 per cent of vital capacity, and predicted maximal mid-expiratory flow. Eosinophils in tissue were negatively correlated with all lung function parameters investigated except predicted forced vital capacity.
Clinicians should be aware of lung function decline in nasal polyps patients, especially in those with tissue eosinophilia.
The effects of different Fe contents (0.168, 0.356 and 0.601 wt%) on microstructures and mechanical properties of the Al–1.6Mg–1.2Si–1.1Cu–0.15Cr–0.15Zr (all in wt%) alloys prepared by low frequency electromagnetic casting process were investigated in the process of solidification, hot extrusion, solid solution and aging treatments. The results show that the increase of Fe content promotes the formation of feathery grains in the process of solidification and the precipitation of another important strengthening phase Q′ with small size. Additionally, it also results in no recrystallization even after solid solution at a high temperature of 550 °C, which is because of the increase number of elliptical shaped and fine DO22-Al3Zr dispersoids (∼70 nm long and ∼35 nm wide) and the spherical or elliptical shaped Fe-containing phases. When Fe content of the alloy increases to 0.356 wt%, both the ultimate tensile strength and yield strength of the alloy-T6 increase by more than 60 MPa and with little cost of ductility.
In this paper, field effect transistors (FET) based on different kinds of non-graphene materials are introduced, which are MoS2, WSe2 and black phosphorus (BP). Those devices have their unique features in fabrication process compared with conventional FETs. Among them, MoS2 FET shows better electrical characteristics by applying a SiO2 protective layer; WSe2 FET is fabricated based on a new low pressure chemical vapor deposition (LPCVD) method; BP FET acquires high on/off ratio and high hole mobility by using a simple dry transfer method. Those novel non-graphene materials inspire new design and fabrication process of basic logic device.