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1.
Phys Rev Lett ; 130(14): 146101, 2023 Apr 07.
Article En | MEDLINE | ID: mdl-37084444

Because of the half-filled t_{2g}-electron configuration, the BO_{6} octahedral distortion in a 3d^{3} perovskite system is usually very limited. In this Letter, a perovskitelike oxide Hg_{0.75}Pb_{0.25}MnO_{3} (HPMO) with a 3d^{3} Mn^{4+} state was synthesized by using high pressure and high temperature methods. This compound exhibits an unusually large octahedral distortion enhanced by approximately 2 orders of magnitude compared with that observed in other 3d^{3} perovskite systems like RCr^{3+}O_{3} (R=rare earth). Essentially different from centrosymmetric HgMnO_{3} and PbMnO_{3}, the A-site doped HPMO presents a polar crystal structure with the space group Ama2 and a substantial spontaneous electric polarization (26.5 µC/cm^{2} in theory) arising from the off-center displacements of A- and B-site ions. More interestingly, a prominent net photocurrent and switchable photovoltaic effect with a sustainable photoresponse were observed in the current polycrystalline HPMO. This Letter provides an exceptional d^{3} material system which shows unusually large octahedral distortion and displacement-type ferroelectricity violating the "d^{0}-ness" rule.

2.
Zhonghua Yu Fang Yi Xue Za Zhi ; 56(12): 1880-1888, 2022 Dec 06.
Article Zh | MEDLINE | ID: mdl-36536582

Gene fusion is one of the mechanisms that promote tumor development. It is also an important cause for the poor prognosis of patients. The detection of gene fusion is crucial for the recognition of tumor biomarker, cancer subtype classification, and clinical medication guidance. Appropriate methods can help the early diagnosis and avoid ineffective medication. Traditional tests include fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), reverse transcription of PCR (RT-PCR), and next generation sequencing (NGS). The next generation sequencing (NGS) mainly includes: whole genome sequencing (WGS), whole transcriptome sequencing (WTS) and target sequencing (hybridization capture method/amplicon method). In clinical concomitant diagnostic applications, some factors such as operability, time/money costs, and the level of expertise required for data analysis should be considered. This article concludes with a discussion of the technical principles of different detection methods and advantages/limitations. Meanwhile, it provides reference opinions for the detection methods of gene fusion.


Lung Neoplasms , Neoplasms , Humans , High-Throughput Nucleotide Sequencing/methods , In Situ Hybridization, Fluorescence , Neoplasms/genetics , Gene Fusion , Technology , Lung Neoplasms/diagnosis
3.
Nat Commun ; 13(1): 7906, 2022 Dec 23.
Article En | MEDLINE | ID: mdl-36550120

Electron quasiparticles play a crucial role in simplifying the description of many-body physics in solids with surprising success. Conventional Landau's Fermi-liquid and quasiparticle theories for high-temperature superconducting cuprates have, however, received skepticism from various angles. A path-breaking framework of electron fractionalization has been established to replace the Fermi-liquid theory for systems that show the fractional quantum Hall effect and the Mott insulating phenomena; whether it captures the essential physics of the pseudogap and superconducting phases of cuprates is still an open issue. Here, we show that excitonic excitation of optimally doped Bi2Sr2CaCu2O8+δ with energy far above the superconducting-gap energy scale, about 1 eV or even higher, is unusually enhanced by the onset of superconductivity. Our finding proves the involvement of such high-energy excitons in superconductivity. Therefore, the observed enhancement in the spectral weight of excitons imposes a crucial constraint on theories for the pseudogap and superconducting mechanisms. A simple two-component fermion model which embodies electron fractionalization in the pseudogap state provides a possible mechanism of this enhancement, pointing toward a novel route for understanding the electronic structure of superconducting cuprates.

4.
Zhonghua Yu Fang Yi Xue Za Zhi ; 56(5): 574-582, 2022 May 06.
Article Zh | MEDLINE | ID: mdl-35644970

Objective: To investigate the characteristics of non-alcoholic fatty liver disease (NAFLD) and its associated factors in rheumatoid arthritis (RA) patients. Methods: This cross-sectional study recruited 385 RA patients [including 72 (18.7%) male and 313 (81.3%) female] who received abdominal sonographic examination from August 2015 to May 2021 at Department of Rheumatology, Sun Yat-Sen Memorial Hospital. There were 28 RA patients at 16-29 years old and 32, 80, 121, 99, 25 at 30-39, 40-49, 50-59, 60-69, ≥ 70 years old, respectively. Demographic and clinical data were collected including age, gender, history of alcohol consumption, disease duration, body mass index (BMI), waist circumference, blood pressure, RA disease activity indicators and previous medications. Logistic regression analyses were used to identify the associated factors of NAFLD in RA patients. Results: The prevalence of NAFLD was 24.2% (93/385) in RA patients, 26.3% (21/80) in 40-49 age group and 33.1% (40/121) in 50-59 age group. There were 22.1% (85/385) and 3.6% (14/385) RA patients with overweight and obese, in which the prevalence of NAFLD was 45.9% (39/85) and 78.6% (11/14) respectively, which was 2.6 folds and 4.5 folds that of RA patients with normal BMI. Although there was no significant difference of age, gender and RA disease activity indicators between RA patients with or without NAFLD, those with NAFLD had higher proportions of metabolic diseases including obese (11.8% vs. 1.0%), central obesity (47.3% vs. 16.8%), hypertension (45.2% vs. 29.8%) and type 2 diabetes mellitus (24.7% vs. 12.0%), consistent with higher levels of total cholesterol [(5.33±1.31) mmol/L vs. (4.73±1.12) mmol/L], triglyceride [(1.51±1.08) mmol/L vs. (0.98±0.54) mmol/L] and low-density lipoprotein cholesterol [(3.37±0.97) mmol/L vs. (2.97±0.78) mmol/L, all P<0.05]. Multivariate logistic regression analysis showed that BMI (OR=1.314) and triglyceride (OR=1.809) were the independent factors positively associated with NAFLD in RA patients. Conclusion: NAFLD is a common comorbidity in RA patients, especially in those with middle-aged, overweight or obese, which is associated with high BMI or high triglyceride. Screening and management of NAFLD in RA patients especially those with overweight, obese or dyslipidemia should be emphasized.


Arthritis, Rheumatoid , Non-alcoholic Fatty Liver Disease , Adolescent , Adult , Aged , Arthritis, Rheumatoid/complications , Arthritis, Rheumatoid/epidemiology , Cholesterol, LDL , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Non-alcoholic Fatty Liver Disease/epidemiology , Obesity/complications , Obesity/epidemiology , Overweight/complications , Overweight/epidemiology , Triglycerides , Young Adult
5.
Zhonghua Yu Fang Yi Xue Za Zhi ; 56(3): 397-400, 2022 Mar 06.
Article Zh | MEDLINE | ID: mdl-35381666

This study analyzed the characteristics and change trend of Guangzhou citizens' demands related to vaccination through government hotlines 12345 and 12320 from 2018 to 2020. It understood the hotspots and needs of the public for vaccination work, analyzed the problems existing in vaccination work, and provided reference and suggestions for health departments to improve vaccination services and formulate relevant policies: to timely improve the professional ability and knowledge reserve of hotline personnel; to strengthen the construction of vaccination service system;to optimize the appointment vaccination service application; to scientifically purchase HPV vaccine and ensure the production and supply of vaccine.


Hotlines , Papillomavirus Vaccines , Government , Humans , Vaccination
6.
Zhonghua Nei Ke Za Zhi ; 61(2): 193-199, 2022 Feb 01.
Article Zh | MEDLINE | ID: mdl-35090255

Objective: To investigate the characteristics of functional limitation and associated factors in patients with rheumatoid arthritis (RA). Methods: Consecutive patients with RA were recruited from August 2015 to June 2019 at Department of Rheumatology, Sun Yat-Sen Memorial Hospital. Demographic and clinical characteristics including age, gender, erythrocyte sedimentation rate (ESR), visual analogue scale (VAS) of pain, clinical disease activity index (CDAI), modified total Sharp score were collected. Physical function was assessed by the Stanford health assessment questionnaire disability index (HAQ-DI).Ordered logistic regression was used to analyze the related factors of HAQ-DI. Results: A total of 643 RA patients were finally recruited including 114 males and 529 females with mean age (49.7±12.9) years. There were 399 (62.1%) patients having different degrees of functional limitation, who were classified as mild (293, 45.6%), moderate (73, 11.4%) and severe (33, 5.1%). The prevalence of functional limitation was positively correlated with age and disease activity. The most restricted activity was walking [43.5% (280/643)], followed by gripping [36.1% (232/643)], reaching [35.5% (228/643)], daily activities [33.4% (215/643)], hygiene [33.0% (212/643)], dressing and grooming [29.7% (191/643)] and arising [29.1% (187/643)], and the last eating [18.4% (118/643)]. Multivariate ordered logistic regression analysis showed that age (OR=1.019, 95%CI 1.004-1.035),pain VAS (OR=1.820, 95%CI 1.616-2.050), ESR (OR=1.009, 95%CI 1.001-1.017), CDAI (OR=1.080, 95%CI 1.059-1.102) and modified total Sharp score (OR=1.010, 95%CI 1.004-1.015) were associated factors of functional limitation. Conclusion: The majority RA patients have functional limitation. Age, pain and active disease are independent associated factors. Therefore, target treatment and control of pain should be emphasized in RA patients.


Arthritis, Rheumatoid , Adult , Blood Sedimentation , Female , Humans , Logistic Models , Male , Middle Aged , Pain , Surveys and Questionnaires
7.
J Synchrotron Radiat ; 28(Pt 3): 977-986, 2021 May 01.
Article En | MEDLINE | ID: mdl-33950006

We report on the development of a high-resolution and highly efficient beamline for soft X-ray resonant inelastic X-ray scattering (RIXS) located at the Taiwan Photon Source. This beamline adopts an optical design that uses an active grating monochromator (AGM) and an active grating spectrometer (AGS) to implement the energy compensation principle of grating dispersion. Active gratings are utilized to diminish defocus, coma and higher-order aberrations, as well as to decrease the slope errors caused by thermal deformation and optical polishing. The AGS is mounted on a rotatable granite platform to enable momentum-resolved RIXS measurements with scattering angles over a wide range. Several high-precision instruments developed in-house for this beamline are described briefly. The best energy resolution obtained from this AGM-AGS beamline was 12.4 meV at 530 eV, achieving a resolving power of 4.2 × 104, while the bandwidth of the incident soft X-rays was kept at 0.5 eV. To demonstrate the scientific impact of high-resolution RIXS, we present an example of momentum-resolved RIXS measurements on a high-temperature superconducting cuprate, i.e. La2-xSrxCuO4. The measurements reveal the A1g buckling phonons in superconducting cuprates, opening a new opportunity to investigate the coupling between these phonons and charge-density waves.

8.
J Instrum ; 16(3)2021 Mar.
Article En | MEDLINE | ID: mdl-33868448

Precise quantitative delineation of tumor hypoxia is essential in radiation therapy treatment planning to improve the treatment efficacy by targeting hypoxic sub-volumes. We developed a combined imaging system of positron emission tomography (PET) and electron para-magnetic resonance imaging (EPRI) of molecular oxygen to investigate the accuracy of PET imaging in assessing tumor hypoxia. The PET/EPRI combined imaging system aims to use EPRI to precisely measure the oxygen partial pressure in tissues. This will evaluate the validity of PET hypoxic tumor imaging by (near) simultaneously acquired EPRI as ground truth. The combined imaging system was constructed by integrating a small animal PET scanner (inner ring diameter 62 mm and axial field of view 25.6 mm) and an EPRI subsystem (field strength 25 mT and resonant frequency 700 MHz). The compatibility between the PET and EPRI subsystems were tested with both phantom and animal imaging. Hypoxic imaging on a tumor mouse model using 18F-fluoromisonidazole radio-tracer was conducted with the developed PET/EPRI system. We report the development and initial imaging results obtained from the PET/EPRI combined imaging system.

9.
Scand J Rheumatol ; 50(4): 280-289, 2021 Jul.
Article En | MEDLINE | ID: mdl-33554691

Objective: Little is known about muscle wasting in elderly patients with rheumatoid arthritis (RA). We examined muscle characteristics and their clinical significance in this group.Method: Consecutive RA patients were recruited and clinical data were collected. Muscle mass and distribution were assessed using bioelectric impedance analysis. Myopenia was defined as an appendicular skeletal muscle mass index (ASMI) ≤ 7.0 kg/m2 (men) and ≤ 5.7 kg/m2 (women).Results: Among the 643 RA patients recruited, 165 (25.7%) were elderly patients (age ≥ 60 years) with a mean age of 65.1 ± 4.5 years. Compared with young patients (age < 60 years), elderly RA patients had significantly higher Disease Activity Score based on 28-joint count-C-reactive protein (DAS28-CRP) (median 3.4 vs 3.2), Health Assessment Questionnaire Disability Index (HAQ-DI) (0.38 vs 0.13), and modified total Sharp score (mTSS) (16 vs 9), and a higher proportion of myopenia (54.5% vs 41.4%; all p < 0.01). Elderly RA patients with myopenia (n = 90, 14.0%) had significantly higher DAS28-CRP (3.6 vs 3.0), HAQ-DI (0.50 vs 0.12), and mTSS (21 vs 7) than young RA patients without myopenia (n = 280, 43.5%; all p < 0.0083). Multivariate logistic and linear regression analyses showed that myopenia, high HAQ-DI, active smoking, hypertension, diabetes, and coronary atherosclerotic heart disease were the main relevant characteristics of elderly RA patients. Age positively correlated with HAQ-DI, and ASMI negatively correlated with HAQ-DI (both p < 0.01). Further mediation analysis showed that ASMI partially mediated the association between age and HAQ-DI.Conclusion: Our data reveal that half of elderly RA patients manifest myopenia which aggravates physical dysfunction as a mediator of age. Myopenia, a neglected complication in elderly RA patients, should be recognized and further investigated.


Arthritis, Rheumatoid/complications , Muscular Atrophy/etiology , Adult , Aged , Arthritis, Rheumatoid/physiopathology , Cross-Sectional Studies , Disability Evaluation , Female , Humans , Male , Middle Aged , Muscular Atrophy/physiopathology
10.
Zhonghua Nei Ke Za Zhi ; 60(2): 128-133, 2021 Feb 01.
Article Zh | MEDLINE | ID: mdl-33503723

Objective: To investigate the value of baseline anti-mutated citrullinated vimentin (MCV) antibody for predicting one-year radiographic progression in patients with rheumatoid arthritis (RA). Methods: Consecutive RA patients were recruited from November 2014 to July 2018 at Department of Rheumatology, Sun Yat-sen Memorial Hospital, Clinical data were collected including disease activity score in 28 joints with four variables including C-reactive protein (CRP).Serum anti-MCV antibody at baseline was detected by enzyme-linked immunosorbent assay. X ray assessment of both hands/wrists was performed and assessed according to the Sharp/van der Heijde modified score (mTSS) at baseline and the 12th month. Univariate and multivariate logistic regression analyses were used to identify the risk factors for one-year radiographic progression. Results: Among 220 RA patients recruited, the positive rate of anti-MCV antibody at baseline was 77.7%. Compared with those with negative anti-MCV antibody, RA patients with positive anti-MCV antibody had higher disease activity score in 28 joints with four variables induding CRP [3.8 (2.4, 5.0) vs. 3.1 (2.1, 4.0), P=0.007], more physical dysfunction (21.6% vs. 8.2%, P=0.033) and higher radiographic indicators including mTSS [11 (2, 27) vs. 4 (1, 10), P=0.003], joint space narrowing [JSN, 4 (0, 14) vs. 2 (0, 6), P=0.024] and joint erosion[JE, 5 (1, 18)vs. 3 (0, 5), P=0.003]. After one-year follow-up, sixty-six RA patients (30.0%) developed radiographic progression, the percentage of whom was significantly higher in positive anti-MCV group than that in negative anti-MCV group (33.9% vs.16.3%, P=0.018). Multivariate logistic regression analysis suggested that positive anti-MCV antibody at baseline was an independent risk factor for one-year radiographic progression (OR=2.341, 95%CI 1.002-5.469). Conclusion: Positive anti-MCV antibody at baseline predicts one-year radiographic progression in RA patients. In the future, anti-MCV antibody can be used not only as a supplementary laboratory marker, but also in disease activity assessment and prognosis prediction for RA.


Arthritis, Rheumatoid , Peptides, Cyclic , Arthritis, Rheumatoid/diagnostic imaging , Autoantibodies , Biomarkers , Disease Progression , Humans , Vimentin
11.
Sci Rep ; 10(1): 18012, 2020 Oct 22.
Article En | MEDLINE | ID: mdl-33093480

We have successfully grown centimeter-sized layered [Formula: see text] single crystals under high oxygen pressures of 120-150 bar by the floating zone technique. This enabled us to perform neutron scattering experiments where we observe close to quarter-integer magnetic peaks below [Formula: see text] that are accompanied by steep upwards dispersing spin excitations. Within the high-frequency Ni-O bond stretching phonon dispersion, a softening at the propagation vector for a checkerboard modulation can be observed. We were able to simulate the magnetic excitation spectra using a model that includes two essential ingredients, namely checkerboard charge disproportionation and nano phase separation. The results thus suggest that charge disproportionation is preferred instead of a Jahn-Teller distortion even for this layered [Formula: see text] system.

12.
Article En | MEDLINE | ID: mdl-33612902

We present the development of a PET insert system for potential simultaneous PET/MR imaging using a 9.4 T small animal MRI scanner to test our system. The detectors of the system adopt a strip-line based multiplexing readout method for SiPM signals. In this readout, multiple SiPM outputs in a row share a common strip-line. The position information about a hit SiPM is encoded in the propagation time difference of the signals arriving at the two ends of the strip-line. The use of strip-lines allows us to place the data acquisition electronics remotely from the detector module to greatly simplify the design of the detector module and minimize the mutual electromagnetic interference. The prototype is comprised of 14 detector modules, each of which consists of an 8x4 LYSO scintillator array (each LYSO crystal is 3x3x10 mm3) coupled to two units of Hamamatsu MPPC arrays (4x4, 3.2 mm pitch) that are mounted on a strip-line board. On the strip-line board, outputs of the 32 SiPMs are routed to 2 strip-lines so that 16 SiPM signals share a strip-line. The detector modules are installed inside a plastic cylindrical supporting structure with an inner and outer diameter of 60 mm and 115 mm, respectively, to fit inside a Bruker BioSpec 9.4 Tesla MR scanner. The axial field of view of the prototype is 25.4 mm. The strip-lines were extended by using 5-meter cables to a sampling data acquisition (DAQ) board placed outside the magnet. The detectors were not shielded in the interest of investigating how they may affect and be affected by the MRI. Experimental tests were conducted to evaluate detection performance, and phantom and animal imaging were carried out to assess the spatial resolution and the MR compatibility of the PET insert. Initial results are encouraging and demonstrate that the prototype insert PET can potentially be used for PET/MR imaging if appropriate shielding will be implemented for minimizing the mutual interference between the PET and MRI systems.

13.
Mater Sci Eng C Mater Biol Appl ; 104: 109967, 2019 Nov.
Article En | MEDLINE | ID: mdl-31499981

The statistical proof that most forms of cancer metastasize to bone tissue has redirected research focus to the development of efficient secondary bone cancer treatment regimens. Bisphosphonates (BPs) have been earmarked as a drug of choice for bone metastasis. However, they have a shortcoming of being released before reaching targeted sites due to their low molecular weight. In haste to attain increased efficacy, there is a tendency for drug overdose to occur, resulting in systemic toxicity. One way to curb this is by employing drug delivery systems for targeted and controlled release of the drugs. Having been explored as versatile and innovative drug carriers, multi-walled carbon nanotubes (MWCNTs) have emerged as potential drug delivery systems. Hence, in the present study, alendronate, neridronate and pamidronate are three classes of bisphosphonates that were conjugated onto multi-walled carbon nanotubes. Conjugation was confirmed by characterization techniques including SEM, TEM, EDX, FTIR, Raman and TGA. Drug release studies were also conducted at pH 1.2, 5.5 and 7.4 to study the mechanism of release for neridronate. Results obtained were fitted into Zero order (42.6%), Higuchi (26%) and Korsmeyer-Peppas (22%). The best models describing the release of neridronate from MWCNTs were Zero order, Higuchi and Korsmeyer-Peppas at pH 1.2, 5.5 and 7.4, respectively. A tetrazolium cell viability assay was performed to assess the anticancer activity of the MWCNTs conjugated BPs.


Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Diphosphonates/chemistry , Diphosphonates/pharmacology , Nanotubes, Carbon/chemistry , Cell Line, Tumor , Cell Survival/drug effects , Drug Carriers/chemistry , Drug Delivery Systems/methods , Drug Liberation/drug effects , Humans , Kinetics , MCF-7 Cells
15.
Proc Natl Acad Sci U S A ; 116(25): 12156-12160, 2019 Jun 18.
Article En | MEDLINE | ID: mdl-31109998

The mechanism of superconductivity in cuprates remains one of the big challenges of condensed matter physics. High-T c cuprates crystallize into a layered perovskite structure featuring copper oxygen octahedral coordination. Due to the Jahn Teller effect in combination with the strong static Coulomb interaction, the octahedra in high-T c cuprates are elongated along the c axis, leading to a 3dx 2-y 2 orbital at the top of the band structure wherein the doped holes reside. This scenario gives rise to 2D characteristics in high-T c cuprates that favor d-wave pairing symmetry. Here, we report superconductivity in a cuprate Ba2CuO4-y , wherein the local octahedron is in a very exceptional compressed version. The Ba2CuO4-y compound was synthesized at high pressure at high temperatures and shows bulk superconductivity with critical temperature (T c ) above 70 K at ambient conditions. This superconducting transition temperature is more than 30 K higher than the T c for the isostructural counterparts based on classical La2CuO4 X-ray absorption measurements indicate the heavily doped nature of the Ba2CuO4-y superconductor. In compressed octahedron, the 3d3z 2-r 2 orbital will be lifted above the 3dx 2-y 2 orbital, leading to significant 3D nature in addition to the conventional 3dx 2-y 2 orbital. This work sheds important light on advancing our comprehensive understanding of the superconducting mechanism of high T c in cuprate materials.

16.
Br J Dermatol ; 180(3): 553-558, 2019 03.
Article En | MEDLINE | ID: mdl-30216411

BACKGROUND: Bullous pemphigoid (BP) is the most common autoimmune bullous disease. Whether there is an increased risk for subsequent BP among patients with cancer is still unclear. OBJECTIVES: To evaluate the risk for subsequent BP in patients with cancer. METHODS: This nationwide population-based cohort study was based on data obtained from the Taiwan National Health Insurance Database between 2000 and 2011. A total of 36 838 patients with cancer and 147 352 age-, sex- and index-date-matched controls were recruited. The hazard ratio (HR) of subsequent BP in the patients with cancer was analysed using a Fine-Gray competing risk regression model with mortality as the competing event. RESULTS: The incidence of BP per 100 000 person-years was 17·2 in the patients with cancer and 19·8 in the controls; therefore, the crude incidence rate ratio was 0·87 [95% confidence interval (CI) 0·53-1·36]. The HR of subsequent BP in the patients with cancer was 0·47 (95% CI 0·23-0·94) using the Fine-Gray competing risk regression model. Age (HR 1·05, 95% CI 1·03-1·07), diabetes mellitus (HR 1·69, 95% CI 1·10-2·59) and cerebrovascular disease (HR 2·14, 95% CI 1·36-3·34) were independent risk factors for BP. CONCLUSIONS: The incidence of BP in patients with cancer was not higher than in the control group. Cancer is not a risk factor for BP.


Neoplasms/epidemiology , Pemphigoid, Bullous/epidemiology , Aged , Databases, Factual/statistics & numerical data , Female , Humans , Incidence , Male , Middle Aged , Neoplasms/complications , Pemphigoid, Bullous/etiology , Retrospective Studies , Risk Assessment , Risk Factors , Taiwan/epidemiology
17.
J Dent Res ; 97(4): 451-459, 2018 04.
Article En | MEDLINE | ID: mdl-29202640

Our long-term objective is to devise methods to improve osteotomy site preparation and, in doing so, facilitate implant osseointegration. As a first step in this process, we developed a standardized oral osteotomy model in ovariectomized rats. There were 2 unique features to this model: first, the rats exhibited an osteopenic phenotype, reminiscent of the bone health that has been reported for the average dental implant patient population. Second, osteotomies were produced in healed tooth extraction sites and therefore represented the placement of most implants in patients. Commercially available drills were then used to produce osteotomies in a patient cohort and in the rat model. Molecular, cellular, and histologic analyses demonstrated a close alignment between the responses of human and rodent alveolar bone to osteotomy site preparation. Most notably in both patients and rats, all drilling tools created a zone of dead and dying osteocytes around the osteotomy. In rat tissues, which could be collected at multiple time points after osteotomy, the fate of the dead alveolar bone was followed. Over the course of a week, osteoclast activity was responsible for resorbing the necrotic bone, which in turn stimulated the deposition of a new bone matrix by osteoblasts. Collectively, these analyses support the use of an ovariectomy surgery rat model to gain insights into the response of human bone to osteotomy site preparation. The data also suggest that reducing the zone of osteocyte death will improve osteotomy site viability, leading to faster new bone formation around implants.


Dental Implantation, Endosseous/methods , Dental Implants , Osteotomy/instrumentation , Tooth Socket/surgery , Adult , Aged , Aged, 80 and over , Animals , Cone-Beam Computed Tomography , Female , Femur/surgery , Finite Element Analysis , Humans , Implants, Experimental , Male , Middle Aged , Models, Animal , Molar/surgery , Osseointegration , Ovariectomy , Phenotype , Rats , Rats, Wistar , Tooth Extraction , X-Ray Microtomography
18.
Acta Physiol (Oxf) ; 222(4): e13001, 2018 04.
Article En | MEDLINE | ID: mdl-29178430

AIM: Pregnant women have been recommended to take FA daily to prevent birth defects in the brain and spinal cord. We previously showed that folic acid (FA) exerts an anti-angiogenic activity. As angiogenesis is important for endometrial reorganization and embryonic development, there should be some mechanisms to allow the pregnant mother and the foetus to escape from the FA-induced anti-angiogenesis. This study was designed to investigate the effect of female sex hormones on the FA-induced anti-angiogenic activity. METHODS: The protein levels and protein-protein interaction were examined by Western blot analysis and immunoprecipitation assay respectively. The cell proliferation and migration were examined by MTT assay and wound healing assay respectively. The in vivo angiogenesis was evaluated by Matrigel angiogenesis assay. RESULTS: In human umbilical venous endothelial cells (HUVEC), FA receptor (FR) formed a complex with progesterone receptor (PR), oestradiol receptor (ER) and cSrc. Pregnancy levels of progesterone (P4) or oestradiol (E2) prevented FA-induced inhibitions of proliferation and migration in HUVEC. Both E2 and P4 prevented the FA-induced anti-angiogenesis in vivo. Moreover, cotreatment with FA and P4 or E2 inhibited the signalling pathways involved in FA-induced inhibitions of proliferation and migration in HUVEC. CONCLUSION: Female sex hormones interrupt the FA-induced anti-angiogenic action through receptor-receptor interaction.


Angiogenesis Inhibitors/pharmacology , Estradiol/pharmacology , Folic Acid/pharmacology , Human Umbilical Vein Endothelial Cells/drug effects , Neovascularization, Physiologic/drug effects , Progesterone/pharmacology , Animals , Cell Proliferation/drug effects , Female , Human Umbilical Vein Endothelial Cells/metabolism , Humans , Mice , Pregnancy , Receptors, Estradiol/metabolism , Receptors, Progesterone/metabolism
19.
Phys Rev Lett ; 119(19): 196402, 2017 Nov 10.
Article En | MEDLINE | ID: mdl-29219525

We carried out temperature-dependent (20-550 K) measurements of resonant inelastic x-ray scattering on LaCoO_{3} to investigate the evolution of its electronic structure across the spin-state crossover. In combination with charge-transfer multiplet calculations, we accurately quantified the renomalized crystal-field excitation energies and spin-state populations. We show that the screening of the effective on-site Coulomb interaction of 3d electrons is orbital selective and coupled to the spin-state crossover in LaCoO_{3}. The results establish that the gradual spin-state crossover is associated with a relative change of Coulomb energy versus bandwidth, leading to a Mott-type insulator-to-metal transition.

20.
Rev Sci Instrum ; 88(9): 096107, 2017 Sep.
Article En | MEDLINE | ID: mdl-28964223

In fluorescence spectroscopy and imaging, fluorescence lifetime measurement-assessing the average time fluorophores spend in their excited state before returning to their ground state-offers a number of advantages over quantifying fluorescence intensities that include resistance to photo-bleaching and independence from fluorophore concentration, excitation intensity, and measurement methodology. Despite growing interest, fluorescence lifetime techniques frequently mandate relatively complex instrumentation, slow data acquisition rates, and significant data analyses. In this work, we demonstrate the feasibility of measuring fluorescence lifetimes using off-the-shelf analog silicon photomultipliers and switched-capacitor array waveform sampling techniques, with precision matching that of much larger and more elaborate commercial instruments.

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