188 research outputs found
Curcumin inhibits apoptosis by modulating Bax/Bcl-2 expression and alleviates oxidative stress in testes of streptozotocin-induced diabetic rats
Activity-assisted barrier-crossing of self-propelled colloids over parallel microgrooves
We report a systematic study of the dynamics of self-propelled particles
(SPPs) over a one-dimensional periodic potential landscape, which is fabricated
on a microgroove-patterned polydimethylsiloxane (PDMS) substrate. From the
measured non-equilibrium probability density function of the SPPs, we find that
the escape dynamics of the slow-rotating SPPs across the potential landscape
can be described by an effective potential, once the self-propulsion force is
included into the potential under the fixed angle approximation. This work
demonstrates that the parallel microgrooves provide a versatile platform for a
quantitative understanding of the interplay among the self-propulsion force,
spatial confinement by the potential landscape, and thermal noise, as well as
its effects on activity-assisted escape dynamics and transport of the SPPs
Antibody-based cancer immunotherapy by targeting regulatory T cells
Regulatory T cells (Tregs) are among the most abundant suppressive cells, which infiltrate and accumulate in the tumor microenvironment, leading to tumor escape by inducing anergy and immunosuppression. Their presence has been correlated with tumor progression, invasiveness and metastasis. Targeting tumor-associated Tregs is an effective addition to current immunotherapy approaches, but it may also trigger autoimmune diseases. The major limitation of current therapies targeting Tregs in the tumor microenvironment is the lack of selective targets. Tumor-infiltrating Tregs express high levels of cell surface molecules associated with T-cell activation, such as CTLA4, PD-1, LAG3, TIGIT, ICOS, and TNF receptor superfamily members including 4-1BB, OX40, and GITR. Targeting these molecules often attribute to concurrent depletion of antitumor effector T-cell populations. Therefore, novel approaches need to improve the specificity of targeting Tregs in the tumor microenvironment without affecting peripheral Tregs and effector T cells. In this review, we discuss the immunosuppressive mechanisms of tumor-infiltrating Tregs and the status of antibody-based immunotherapies targeting Tregs
Assessing bilateral ankle proprioceptive acuity in stroke survivors:An exploratory study
BACKGROUND: Bilateral proprioception deficits were reported in stroke survivors. However, whether bilateral proprioception deficits exist in the ankle joint after stroke was unclear. Ankle proprioception is a significant predictor of balance dysfunction after stroke, and previous studies to date are lacking appropriate evaluation methods. OBJECTIVES: We want to determine whether the active movement extent discrimination apparatus (AMEDA) is a reliable tool for assessing ankle proprioceptive acuity in stroke survivors and the presence of deficits in ankle proprioception on the affected and unaffected sides in patients after stroke. METHODS: Bilateral ankle proprioception was assessed in 20 stroke patients and 20 age-matched healthy controls using AMEDA. Test-retest reliability was assessed using the intraclass correlation coefficient (ICC). RESULTS: The ICC in the affected and unaffected sides was 0.713 and 0.74, respectively. Analysis of variance revealed significant deficits in ankle proprioception in subacute stroke survivors vs. healthy controls (F = 2.719, p = 0.045). However, there were no significant differences in proprioception acuity scores between the affected and unaffected sides in patients after stroke (F = 1.14, p = 0.331). CONCLUSIONS: Stroke survivors had bilateral deficits in ankle proprioceptive acuity during active movements compared with age-matched healthy controls, underscoring the need to evaluate these deficits on both sides of the body and develop effective sensorimotor rehabilitation methods for this patient population. The AMEDA can reliably determine bilateral ankle proprioceptive acuity in stroke survivors
Re-channelization of turbidity currents in South China Sea abyssal plain due to seamounts and ridges
Turbidity currents can be characterized as net-erosive, net-depositional or net-bypassing. Whether a flow is erosive, depositional or bypasses depends on the flow velocity, concentration and size but these can also be impacted by external controls such as the degree of confinement, slope gradient and substrate type and erodibility. Our understanding of the relative importance of these controls comes from laboratory experiments and numerical modelling, as well as from field data due to the proliferation of high-resolution 3D seismic and bathymetric data, as well as the outcrop and rock record. In this study, based on extensive multibeam and seismic reflection surveys in combination with International Ocean Discovery Program cores from the South China Sea, we document a new mechanism of turbidity current transformation from depositional to erosive resulting in channel incision. We show how confinement by seamounts and bedrock highs of previously unconfined turbidity currents has resulted in the development of seafloor channels. These channels are inferred to be the result of confinement of flows, which have traversed the abyssal plain, leading to flow acceleration allowing them to erode the seafloor substrate. This interpretation is further supported by the coarsening of flow deposits within the area of the seamounts, indicating that confinement has increased flow competency, allowing turbidity currents to carry larger volumes of coarse sediment which has been deposited in this region. This basin-scale depositional pattern suggests that pre-established basin topography can have an important control on sedimentation which can impact characteristics such as potential hydrocarbon storage
Efficient induction of CD25- iTreg by co-immunization requires strongly antigenic epitopes for T cells
Background: We previously showed that co-immunization with a protein antigen and a DNA vaccine coding for the same antigen induces CD40(low) IL-10(high) tolerogenic DCs, which in turn stimulates the expansion of antigenspecific CD4(+)CD25(-)Foxp3(+) regulatory T cells (CD25(-) iTreg). However, it was unclear how to choose the antigen
sequence to maximize tolerogenic antigen presentation and, consequently, CD25(-) iTreg induction. Results: In the present study, we demonstrated the requirement of highly antigenic epitopes for CD25(-) iTreg
induction. Firstly, we showed that the induction of CD25(-) iTreg by tolerogenic DC can be blocked by anti-MHC-II antibody. Next, both the number and the suppressive activity of CD25(-) iTreg correlated positively with the overt antigenicity of an epitope to activate T cells. Finally, in a mouse model of dermatitis, highly antigenic epitopes derived from a flea allergen not only induced more CD25(-) iTreg, but also more effectively prevented allergenic reaction to the allergen than did weakly antigenic epitopes.
Conclusions: Our data thus indicate that efficient induction of CD25- iTreg requires highly antigenic peptide
epitopes. This finding suggests that highly antigenic epitopes should be used for efficient induction of CD25- iTreg
for clinical applications such as flea allergic dermatitis
Contourite processes associated with the overflow of Pacific Deep Water within the Luzon Trough: Conceptual and regional implications
Overflows through oceanic gateways govern the exchange of water masses in the world's ocean basins. These exchanges also involve energy, salinity, nutrients, and carbon. As such, the physical features that control overflow can exert a strong influence on regional and global climate. Here, we present the first description of sedimentary processes generated by the overflow of Pacific Deep Water (OPDW). This mass flows southward at approximately 2000–3450 m water depth within the Luzon Trough (gateway) from the Pacific Ocean into the South China Sea. OPDW can be divided into: a) a lower, denser layer (including an associated weak counter-current), which has generated a large contourite depositional system (CDS-1) that includes large erosional (channel and moat), depositional (mounded and plastered drift), and mixed (terrace) contourite features along the trough bottom and walls, and b) an upper mixing layer, which has not generated any significant depositional or erosional contourite features. Where OPDW does not reach the seafloor, it is underlain by bottom water that circulates more sluggishly but has generated a second contourite depositional system (CDS-2) made of a large sheet-like drift. The OPDW flow has generally enhanced since the middle to late Miocene, except in the shallower northernmost corridor. In the deeper main trough, reductions in width and depth of the gateway by Taiwan orogenic events have likely accelerated the overflow. The latest significant enhancening may promote widespread development of contourite depositional systems along the South China Sea's lower continental slope and adjacent deeper areas. This work highlights the importance of gateway-confined overflows in controlling the morphology and sedimentary evolution of adjacent deep marine sedimentary systems. A clear understanding of overflow processes and their products is essential for decoding tectonic control in oceanographic or paleoceanographic processes
Chemical composition, antioxidant and antitumor activities of sub-fractions of wild and cultivated Pleurotus ferulae ethanol extracts
Pleurotus ferulae is an edible and medicinal mushroom with various bioactivities. Here, the ethanol extracts of wild and cultivated P. ferulae (PFEE-W and PFEE-C) and their subfractions including petroleum ether (Pe-W/Pe-C), ethyl acetate (Ea-W/Ea-C) and n-butanol (Ba-W/Ba-C) were prepared to evaluate their antioxidant and antitumor activities. Both PFEE-W and PFEE-C show the antioxidant activity and PFEE-W is stronger than PFEE-C. The antioxidant activities of their subfractions are in the following order: Ea > Ba > Pe. Moreover, PFEE-W and PFEE-C significantly inhibit the proliferation of murine melanoma B16 cells, human esophageal cancer Eca-109 cells, human gastric cancer BGC823 cells and human cervical cancer HeLa cells through induction of apoptosis, which partially mediated by reactive oxygen species. The antitumor activities of their subfractions are in the following order: Ea ≥ Pe > Ba. Pe-W shows higher antitumor activity compared with Pe-C, which might be correlated with the difference of their components identified by gas chromatography-mass spectrometry. These results suggest that both wild and cultivated P. ferulae have antioxidant and antitumor activities, and cultivated P. ferulae could be used to replace wild one in some functions
Patients With Obsessive-Compulsive Disorder Exhibit Deficits in Consummatory but Not Anticipatory Pleasure
Background: Reward dysfunctions have been reported in obsessive-compulsive disorder (OCD), which implicates a high possibility of anhedonia for this disease. However, several components of anhedonia, such as consummatory and anticipatory pleasure, has not been substantially studied in OCD patients.Methods: The Chinese version of the Temporal Experience of Pleasure Scale (CV-TEPS) was used to evaluate both the consummatory and anticipatory pleasure in 130 OCD patients, 89 major depressive disorder (MDD) patients, and 95 healthy controls (HCs). The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and the Beck Depression Inventory (BDI) were scored for assessing the severity of obsessive and compulsive symptoms and depressive symptoms, respectively. Analyses of covariance (ANCOVA) were used to compare the differences of anhedonia among the three groups with the severity of depression controlled. Regression analyses were also used to analyze the relationship between consummatory and anticipatory pleasure and clinical variables in OCD patients.Results: After controlling for the effect of depression, there were significant differences in TEPS scores among the three groups (p < 0.05). Compared with HCs, OCD patients had lower scores on the consummatory subscale, but not the anticipatory subscale, of the TEPS. MDD patients had lower scores on both the consummatory and anticipatory subscales than HCs.Conclusion: OCD patients exhibit deficits in consummatory but not anticipatory pleasure, which is distinct from MDD patients
A bibliometric and visualization analysis on the association between chronic exposure to fine particulate matter and cancer risk
Introduction:As one of the major pollutants in ambient air pollution, fine particulate matter (PM2.5) has attracted public attention. A large body of laboratory and epidemiological research has shown that PM2.5 exposure is harmful to human health.MethodsTo investigate its association with the commonly observed PM-related cancer, a bibliometric study was performed on related publications from 2012 to 2021 from a macroscopic perspective with the help of the Web of Science database and scientometric software VOSviewer, CiteSpace V, HistCite, and Biblioshiny.ResultsThe results indicated that of the 1,948 enrolled documents, scientific productions increased steadily and peaked in 2020 with 348 publications. The most prolific authors, journals, organizations, and countries were Raaschou-Nielsen O, Science of the Total Environment, the Chinese Academy of Sciences, and China, respectively. The top five keywords in frequency order were “air pollution,” “particulate matter,” “lung cancer,” “exposure,” and “mortality.”DiscussionThe toxic mechanism of carcinogenicity was explained and is worthy of further investigation. China and the US collaborated most closely, and it is hoped the two countries can strengthen their collaboration to combat air pollution. There is also a need to identify the components of PM2.5 and refine the models to assess the global burden of disease attributed to PM2.5 exposure
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