Therapeutic targets and potential delivery systems of melatonin in osteoarthritis

Osteoarthritis (OA) is a highly prevalent age-related musculoskeletal disorder that typically results in chronic pain and disability. OA is a multifactorial disease, with increased oxidative stress, dysregulated inflammatory response, and impaired matrix metabolism contributing to its onset and progression. The neurohormone melatonin, primarily synthesized by the pineal gland, has emerged as a promising therapeutic agent for OA due to its potential to alleviate inflammation, oxidative stress, and chondrocyte death with minimal adverse effects. The present review provides a comprehensive summary of the current understanding regarding melatonin as a promising pharmaceutical agent for the treatment of OA, along with an exploration of various delivery systems that can be utilized for melatonin administration. These findings may provide novel therapeutic strategies and targets for inhibiting the advancement of OA

Propagating waves in quasi-one dimensional MoO3 ribbons investigated by Raman spectroscopy and scanning near-field optical microscope

National Natural Science Foundation of China [10904171, 10804015, 21173171]; Beijing talent support [2011D005016000005]; Beijing Nova Program [2011079]; Beijing Municipal Natural Science Foundation [1122012]; Natural Science Foundation of Liaoning Province [20102039]; Fundamental Research Funds for the Central Universities [DC10020121, DC10020122, DC10040122]MoO3 ribbons have proven to be a good quasi-one dimensional waveguide. Here, we show that propagating waves can be launched in very thin MoO3 ribbons with the thickness of only 150 nm. By using Raman image method, it was found that the 1/e light damping length at 632.8 nm is 5 similar to 6 mu m. Scanning near-field optical measurement was carried to provide distribution of propagating waves near the surface of the waveguide, where Fabry-Perot interference with the period similar to 0.33 mu m was observed. Furthermore, numerical calculations reveal the guiding waves in thin ribbons are in leak mode with a large portion of energy guided over the MoO3 surface. Applications of these kinds of thin MoO3 ribbons can be found in combined nano-photonic devices and remote surface enhanced Raman sensing. (C) 2012 American Institute of Physics. [doi:10.1063/1.3677972

Arousing Effects of Electroacupuncture on the “Shuigou Point” in Rats with Disorder of Consciousness after Traumatic Brain Injury

Orexin is an important neuropeptide that stimulates cortical activation and arousal and is involved in the regulation of wakefulness and arousal. Our previous meta-analysis showed that acupuncture fared well in the treatment of TBI-induced DOC in which “shuigou (DU 26)” was the most important and frequent point targeted. In the present study, we investigated whether electroacupuncture (EA) promotes TBI-induced unconsciousness wakefulness via orexin pathway. A TBI rat model was established using a control cortical impact (CCI) model. In the stimulated group, TBI rats received EA (15 Hz, 1.0 mA, 15 min). In the antagonist group, TBI rats were intraperitoneally injected with the orexin receptor 1 (OX1R) antagonist SB334867 and received EA. Unconsciousness time was observed in each group after TBI, and electrocorticography (ECoG) was applied to detect rats’ EEG activity. Immunohistochemistry, enzyme-linked immunosorbent assay, and western blot were used to assess the levels of orexin-1(OX1) and OX1R expression in the mPFC. We show that duration of unconsciousness and the ratio of delta power in ECoG in the EA group were significantly reduced compared with those in the TBI group. EA could increase OX1 and OX1R expression in the mPFC and reduced the loss of orexin-producing neurons in LHA. However, all the efficacy of EA was blocked by the OX1R antagonist SB334867. Our findings suggest that EA promotes the recovery of consciousness of TBI-induced unconscious rats via upregulation of OX1and OX1R expression in mPFC

Investigations of the Elongational Deformation Induced by Pins in Pin-Barrel Cold-Feed Extruders

This paper is a study on the elongational deformation induced by pins in pin-barrel cold-feed extruders. The mathematical model is established by using simple flow field, plate model, and Newton constitutive relation. It is proved that there is elongational deformation when the fluid bypasses the pin, and the elongational deformation is quantitatively calculated. The finite element method is used to simulate the flow field of the screw mixing section of the pin-barrel cold-feed extruder with different specifications. The velocity vector nephogram in the simulation results is analyzed by numerical analysis of elongational deformation and compared with the theoretical elongational deformation value. The results show that the simulated and theoretical values of elongational deformation are approximately consistent. The numerical analysis of the key factors affecting the elongational deformation shows that the elongational deformation will gradually increase with the increase of screw diameter. For the screw of the same specification, the increasing helical angle will reduce the elongational deformation, and the increasing rotational speed will linearly increase the elongational deformation in unit time. This study can be used to roughly estimate the elongational deformation induced by pins and establish the mixing theoretical model of the pin-barrel cold-feed extruder

The effect of pore structure on non-Darcy flow in porous media using the lattice Boltzmann method

Non-Darcy flows associated with high Reynolds numbers often occur in the near-wellbore regions of gas reservoirs or hydraulic fractures and thus should not be ignored. However, investigating non-Darcy flow in these porous rocks through laboratory experiments is always expensive and time-consuming. As such, this article sought an alternative method, and a lattice Boltzmann study of non-Darcy flow in various porous models was performed. The applicability of two non-Darcy correlations in porous media and the effect of pore structure on non-Darcy flow were examined. In addition, the reasons for the deviation from the linear Darcy flow and different flow patterns related to inertial effects of the fluid were also studied. The results showed that the characterization of non-Darcy flow in porous media with the cubic law can only be valid in a narrow range of Reynolds number beyond the Darcy regime, outside of which the strong inertia-dominated flow yields to the quadratic correction. On the whole, representing the non-Darcy flows using the quadratic correction is acceptable, especially for porous media with a higher complexity. The features of non-Darcy flow greatly depend on the pore structure of a porous medium, and more heterogeneous pore models always have a faster cessation for Darcy flow and a higher beta factor. Furthermore, for simple porous media a small amount of parameters may be adequate for the prediction of the beta factor; while the correlations involving more parameters would be needed to determine the beta factor for more intricate porous models, although such correlations may not be widely used in various industries. Besides, the non-Darcy flow that occurs in porous media is collectively controlled by different mechanisms. At elevated velocities, the inertial core effect in a large channel will lead the flow to be more homogeneous and less tortuous, while in porous models with complicated pore space, the steady eddy and reversal flow resulting from drag force will make the flow paths more tortuous. As such, it is the hope of this study to provide some new insights into the non-Darcy flow in porous media

A stand-alone Co mineral deposit in northeastern Hunan Province, South China: Its timing, origin of ore fluids and metal Co, and geodynamic setting

The Hengdong cobalt (Co) deposit, located in northeastern Hunan Province of South China, is hosted by the low-grade metamorphic volcaniclastic sedimentary rocks of the early Neoproterozoic Lengjiaxi Group. The Co orebodies strictly controlled by the NE- to ENE-trending Changsha-Pingjiang deep fault zone (CPDFZ) and its secondary structures. Occurring in altered breccias and cataclasites with similar mineral assemblages, Co mineralization is characterized by zoned alteration with predominant silicification and chloritization proximal to the orebodies, and sericitization and carbonatization distal from the mineralization. The integrated field and microscope observations reveal three hydrothermal stages marked by quartz + pyrite + muscovite chalcopyrite of the early-stage mineralization (E-stage), quartz + polymetallic sulfides + chlorite of the middle stage mineralization (M - stage), and quartz + chlorite + carbonate of the late-stage mineralization (L-stage). Muscovite from both the E-stage Co-bearing altered breccia and the CPDFZ mylonite yield Ar-40-Ar-39 plateau ages of 124.7 +/- 0.6 Ma (1 sigma) and 130.3 +/- 1.4 Ma (1 sigma), respectively, indicating an early Cretaceous mineralization likely associated with the last movement of CPDFZ strike-slip shearing. The 8345 values of pyrite and chalcopyrite ranging from -1.5 to -15.9% with a majority between -7.5 and -15.9%, and the lead isotope compositions of the pyrite (Pb-206/Pb-204 = 18.156-18.761, Pb-207/Pb-204 = 15.645-15.662 and Pb-208/Pb-204 = 38.469-39.172) overlapping with those of upper crust, indicate a main crust-derived source. The chemical compositions of pyrite further indicate the ore fluids and metal Co of the Hengdong deposit are most likely linked to the meta-mafic and volcanic rocks of the Neoarchean to Paleoproterozoic Lianyunshan Group, but with a contamination by the wall rocks of Lengjiaxi Group and Lianyunshan granitoids. Fluid inclusion investigations from Hengdong deposit reveal the decreasing homogenization temperatures from similar to 250 to 320 degrees C (peak of 280-300 degrees C) at the E stage, through similar to 220-320 degrees C (peak of 270-300 degrees C) at the M stage, and to similar to 150-230 degrees C at the L stage without obviously salinity (7.0-15 wt% NaCI equiv.) changed. In the M - stage, the presence of coexisting LV inclusions and V-rich inclusions with the similar homogenization temperature, consistent with the chlorite geothermometry data, is interpreted to be the result of fluid immiscibility, which was caused by cyclic pressure release during fault-zone movement. Combined with the Late Mesozoic tectonism of South China, the present data support the Hengdong deposit formed under an extension-associated tectonic regime most likely induced by slab roll-back of the subducted Paleo-Pacific Plate during the early Cretaceous. This extensional event not only caused the reactivation of the pre-existing structures as manifested by the CPDFZ characteristic of stress transformation from compression to extension but also likely resulted in the release of large amounts of Co-bearing ore fluids from the Proterozoic or older volcanogenic rocks. When the ore fluids migrated along the CPDFZ and its secondary faults, the decompression (adiabatic cooling) of the hydrothermal fluids shifted the ore fluid to the immiscibility field, significantly reduced the degree of cobalt undersaturation, and caused cobalt to precipitate, which finally formed the Hengdong Co mineral deposit

The spatial–temporal evolution of the Asian summer monsoon during the late Miocene and potential CO2 forcing: A data–model comparison

The long-term evolution of the Asian summer monsoon and its drivers are important for understanding future Asian summer monsoon variations. Due to inconsistencies among proxy data and/or different interpretations, controversies remain regarding the long-term evolution and drivers of the East and South Asian summer monsoons (EASM and SASM) during the late Miocene. There are two main viewpoints involving an overall strengthening or weakening trend, which is typically attributed to uplift of the Himalaya–Tibetan Plateau or global cooling. A detailed synthesis of paleoenvironmental reconstructions is required to understand the evolution of the EASM and SASM during the late Miocene. Here, we compiled paleoenvironmental reconstructions for the EASM and SASM during the late Miocene and used numerical simulations to investigate their evolution and potential drivers. The synthesis of the paleoenvironmental reconstructions indicates that the late Miocene climate: (1) underwent an overall drying trend in northern China, but a wetting trend in the South China Sea and surrounding areas; and (2) became progressively drier on the northern Indian subcontinent, but not on the southern Indian subcontinent. The modeling results indicate that: (1) EASM circulation overall weakened, whereas SASM circulation weakened (strengthened) in the northern (southern) part of South Asian monsoon domain; (2) summer precipitation decreased (increased) in the northern (southern) part of East and South Asian monsoon domains, which is roughly agreement with the paleoclimate records. Our results suggest that a decline in atmospheric CO2 may have been a key driver of the evolution of the EASM and SASM during the late Miocene