Brain regulates weight bearing bone through PGE2 skeletal interoception: implication of ankle osteoarthritis and pain

Bone is a mechanosensitive tissue and undergoes constant remodeling to adapt to the mechanical loading environment.However,it is unclear whether the signals of bone cells in response to mechanical stress are processed and interpreted in the brain.In this study,we found that the hypothalamus of the brain regulates bone remodeling and structure by perceiving bone prostaglandin E2(PGE2)concentration in response to mechanical loading.Bone PGE2 levels are in proportion to their weight bearing.When weight bearing changes in the tail-suspension mice,the PGE2 concentrations in bones change in line with their weight bearing changes.Deletion of cyclooxygenase-2(COX2)in the osteoblast lineage cells or knockout of receptor 4(EP4)in sensory nerve blunts bone formation in response to mechanical loading.Moreover,knockout of TrkA in sensory nerve also significantly reduces mechanical load-induced bone formation.Moreover,mechanical loading induces cAMP-response element binding protein(CREB)phosphorylation in the hypothalamic arcuate nucleus(ARC)to inhibit sympathetic tyrosine hydroxylase(TH)expression in the paraventricular nucleus(PVN)for osteogenesis.Finally,we show that elevated PGE2 is associated with ankle osteoarthritis(AOA)and pain.Together,our data demonstrate that in response to mechanical loading,skeletal interoception occurs in the form of hypothalamic processing of PGE2-driven peripheral signaling to maintain physiologic bone homeostasis,while chronically elevated PGE2 can be sensed as pain during AOA and implication of potential treatment.

Preliminary report of the September 5,2022 M_(S) 6.8 Luding earthquake,Sichuan,China

The 2022 M_(S)6.8 Luding earthquake is the strongest earthquake in Sichuan Province, Western China, since the 2017 M_(S)7.0 Jiuzhaigou earthquake. It occurred on the Moxi fault in the southeastern segment of the Xianshuihe fault, a tectonically active and mountainous region with severe secondary earthquake disasters. To better understand the seismogenic mechanism and provide scientific support for future hazard mitigation, we summarize the preliminary results of the Luding earthquake, including seismotectonic background, seismicity and mainshock source characteristics and aftershock properties, and direct and secondary damage associated with the mainshock.The peak ground displacements in the NS and EW directions observed by the nearest GNSS station SCCM are ~35 mm and ~55 mm, respectively, resulting in the maximum coseismic dislocation of 20 mm along the NWW direction, which is consistent with the sinistral slip on the Xianshuihe fault. Back-projection of teleseismic P waves suggest that the mainshock rupture propagated toward south-southeast. The seismic intensity of the mainshock estimated from the back-projection results indicates a Mercalli scale of Ⅷ or above near the ruptured area,consistent with the results from instrumental measurements and field surveys. Numerous aftershocks were reported, with the largest being M_(S)4.5. Aftershock locations(up to September 18, 2022) exhibit 3 clusters spanning an area of 100 km long and 30 km wide. The magnitude and rate of aftershocks decreased as expected, and the depths became shallower with time. The mainshock and two aftershocks show left-lateral strike-slip focal mechanisms. For the aftershock sequence, the b-value from the Gutenberg-Richter frequency-magnitude relationship, h-value, and p-value for Omori’s law for aftershock decay are 0.81, 1.4, and 1.21, respectively, indicating that this is a typical mainshock-aftershock sequence. The low b-value implies high background stress in the hypocenter region. Analysis from remote sensing satellite images and UAV data shows that the distribution of earthquake-triggered landslides was consistent with the aftershock area. Numerous small-size landslides with limited volumes were revealed, which damaged or buried the roads and severely hindered the rescue process.

Effect of silicon precursor on silicon incorporation in SAPO-11 and their catalytic performance for hydroisomerization of n-octane on Pt-based catalysts

SAPO-11 molecular sieves were synthesized using silica sol, hydrophilic fumed silica, and tetraethyl orthosilicate（TEOS） as silicon precursors. Their physicochemical properties were characterized using XRD,SEM, nitrogen adsorption-desorption, Py-IR, NH;-TPD, EDS, and;Al,;P,;Si MAS NMR techniques. The catalytic performance was assessed in the hydroisomerization of n-octane. The results showed that the silicon precursors influenced the physicochemical properties and catalytic performance of SAPO-11. SAPO-11 synthesized using hydrophilic fumed silica as silicon precursor showed higher silicon distribution and had more medium acid sites. SAPO-11 synthesized using TEOS as silicon precursor had more silicon content, but more silicon islands formed in its framework. The depolymerization of silicon precursors might affect the silicon content and distribution in SAPO-11. In the hydroisomerization of n-octane, the catalytic activity strongly depended on the number of medium acid sites instead of the number of total acid sites.SAPO-11 synthesized using hydrophilic fumed silica as silicon precursor exhibited higher catalytic activity than the other samples because it has more medium acid sites.

Aβ-Aggregation-Generated Blue Autofluorescence Illuminates Senile Plaques as well as Complex Blood and Vascular Pathologies in Alzheimer’s Disease

Senile plaque blue autofluorescence was discovered around 40 years ago,however,its impact on Alzheimer’s disease(AD)pathology has not been fully examined.We analyzed senile plaques with immunohistochemistry and fluorescence imaging on AD brain sections and also Aβ aggregation in vitro.In DAPI or Hoechst staining,the nuclear blue fluorescence could only be correctly assigned after subtracting the blue plaque autofluorescence.The flower-like structures wrapping dense-core blue fluorescence formed by cathepsin D staining could not be considered central-nucleated neurons with defective lysosomes since there was no nuclear staining in the plaque core when the blue autofluorescence was subtracted.Both Aβ self-oligomers and Aβ/hemoglobin heterocomplexes generated blue autofluorescence.The Aβ amyloid blue autofluorescence not only labels senile plaques but also illustrates red cell aggregation,hemolysis,cerebral amyloid angiopathy,vascular plaques,vascular adhesions,and microaneurysms.In summary,we conclude that Aβ-aggregation-generated blue autofluorescence is an excellent multi-amyloidosis marker in Alzheimer’s disease.

Terrain relief periods of loess landforms based on terrain profiles of the Loess Plateau in northern Shaanxi Province,China

The Loess Plateau is densely covered by numerous types of gullies which represent different soil erosion intensities.Therefore,research on topographic variation features of the loess gullies is of great significance to environmental protection and ecological management.Using a5 m digital elevation model and data from a national geographic database,this paper studies different topographical areas of the Loess Plateau,including Shenmu,Suide,Yanchuan,Ganquan,Yijun,and Chunhua,to derive representative gully terrain profile data of the sampled areas.First,the profile data are standardized in MATLAB and then decomposed using the ensemble empirical mode decomposition method.Then,a significance test is performed on the results;the test confidence is 95% to 99%.The most reliable decomposition component is then used to calculate the relief period and size of the gullies.The results showed that relief periods of the Chunhua,Shenmu,Yijun,Yuanchuan,Ganquan,and Suide gullies are 1110.14 m,1096.85 m,1002.49 m,523.48 m,498.12 m,and 270.83 m,respectively.In terms of gully size,the loess landforms are sorted as loess fragmented tableland,aeolian and dune,loess tableland,loess ridge,loess hill and loess ridge,and loess hill,in descending order.Taken together,the gully terrain features of the sample areas and the results of the study are approximately consistent with the actual terrain profiles.Thus,we conclude that ensemble empirical mode decomposition is a reliable method for the study of the relief and topography of loess gullies.

Low-latency full-field temporal magnification based on spectral compression

Temporal magnification is an emerging technology for the observation of single-shot optical signals with irregular and ultrafast dynamics,which exceed the speed,precision,and record length of conventional digitizers.Conventional temporal magnification schemes suffer from transmission delay and large volume of dispersive elements.Because only the signal envelope can be magnified in the dispersion-based schemes,real-time full-field(phase and amplitude)measurement for a complex ultrafast optical signal remains an open challenge.Here,a bandwidth-compressed temporal magnification scheme for low-latency full-field measurements of ultrafast dynamics is proposed.Unlike the dispersion-based schemes,temporal magnification of a complex optical signal is achieved by bandwidth compression.The bandwidth is coherently compressed by the Vernier effect relying on the detuned free spectral range of a periodic optical filter and time lens.Experimentally,a temporal magnification factor of 224 is realized,and full-field measurements for picosecond pulses are demonstrated.The proposal eliminates the dependence on dispersive elements and shows great potential in integration,which may pave a new path toward full-field measurement for nonrepetitive and statistically rare signals.