聚甲基丙烯酸甲酯強化和修復椎弓根螺釘的生物力學研究

Objective To evaluate pedicle screw fixation strength following augmentation and restoration with polymethylmethacrylate (PMMA). Methods Compact CD (CCD) screws of 6.0 mm diameter was implanted into the pedicle unilaterally. And a pilot hole was created using 3.5 mm drill contralaterally on eight fresh human lower lumbar vertebrae (L 3-5).Neither the screws nor the drillings penetrated the anterior cortex of the vertebral bodies. The screws were pulled out from the vertebrae at 5 mm/min. The screw track and the pilot hole were filled with 3-5 ml of PMMA. Then, the screws were implanted bilaterally, and the PMMA was allowed to harden for 1 hour. Morphology of PMMA around the screws was observed by section of the vertebrae along the screw. Results Pullout force of pedicle screw fixation in normal vertebrae was (825.5±254.7) N and (1 711.1±488.8)N following augmentation with PMMA. Restoration of a pullout pedicle screw fixation with PMMA was able to salvage pullout force to (1 832.4±497.4) N. The pullout forces following augmentation and restoration were significantly greater than that in normal vertebrae. Morphology of PMMA around the screws was related to the viscosity of PMMA during injection. No PMMA was found in vertebral canal or surface of pedicle. Conclusion Augmentation and restoration with PMMA offered a significantly increase of strength for pedicle screw fixation, and could be used clinically in case of failure of pedicle screw fixation. 目的 評價聚甲基丙烯酸甲酯(polymethylmethacrylate ,PMMA)強化和修復椎弓根螺釘固定的生物力學效果。方法8具成人新鮮腰椎骨L3～5,隨機選擇一側椎弓根放置直徑為6.0mm的CCD(compactCD)椎弓根螺釘 ,另一側以直徑為3.5mm的鉆頭導孔 ,均不穿透椎體前皮質。在材料試驗機上進行椎弓根螺釘拔出實驗 ,拔出速率為5mm/min。然后沿椎弓根孔道注入PMMA粉和水按體積1∶2混合的PMMA強化修復材料3～5ml,雙側椎弓根分別使用與前相同的CCD椎弓根螺釘 ,室溫下1h后再行前述拔出實驗。沿椎弓根螺釘長度方向鋸開標本 ,觀察PMMA在螺釘孔道中的分布范圍。結果CCD椎弓根螺釘在正常椎弓根內的最大拔出力為 (825.5±254.7)N ;在經強化后的正常椎弓根內和在修復失效的椎弓根內 ,CCD椎弓根螺釘最大拔出力分別為 (1711.1±488.8)N和 (1832.4±497.4)N ,高于正常椎弓根螺釘的最大拔出力 ,差異有顯著性意義(P<0.01)。PMMA在螺釘周圍的分布與其注入時的粘稠度有關 ,未見椎管內或椎弓根外有PMMA分布。結論沿椎弓根孔道注入PMMA可顯著增加椎弓根螺釘的拔出力 ,適用于螺釘松動和拔出的修復固

FTO influences adipogenesis by regulating mitotic clonal expansion

The fat mass and obesity-associated (FTO) gene plays a pivotal role in regulating body weight and fat mass; however, the underlying mechanisms are poorly understood. Here we show that primary adipocytes and mouse embryonic fibroblasts (MEFs) derived from FTO overexpression (FTO-4) mice exhibit increased potential for adipogenic differentiation, while MEFs derived from FTO knockout (FTO-KO) mice show reduced adipogenesis. As predicted from these findings, fat pads from FTO-4 mice fed a high-fat diet show more numerous adipocytes. FTO influences adipogenesis by regulating events early in adipogenesis, during the process of mitotic clonal expansion. The effect of FTO on adipogenesis appears to be mediated via enhanced expression of the pro-adipogenic short isoform of RUNX1T1, which enhanced adipocyte proliferation, and is increased in FTO-4 MEFs and reduced in FTO-KO MEFs. Our findings provide novel mechanistic insight into how upregulation of FTO leads to obesity

Measurement of the matrix element for the decay η′→ηπ +π -

The Dalitz plot of η⊃′→ηπ⊃+π⊃- decay is studied using (225.2±2.8)×106 J/ψ events collected with the BESIII detector at the BEPCII e⊃+e⊃- collider. With the largest sample of η⊃′ decays to date, the parameters of the Dalitz plot are determined in a generalized and a linear representation. Also, the branching fraction of J/ψ→γη⊃′ is determined to be (4.84±0.03±0.24)×10⊃-3, where the first error is statistical and the second systematic. © 2011 American Physical Society.published_or_final_versio

Linkage Mapping of Stem Saccharification Digestibility in Rice

Rice is the staple food of almost half of the world population, and in excess 90% of it is grown and consumed in Asia, but the disposal of rice straw poses a problem for farmers, who often burn it in the fields, causing health and environmental problems. However, with increased focus on the development of sustainable biofuel production, rice straw has been recognized as a potential feedstock for non-food derived biofuel production. Currently, the commercial realization of rice as a biofuel feedstock is constrained by the high cost of industrial saccharification processes needed to release sugar for fermentation. This study is focused on the alteration of lignin content, and cell wall chemotypes and structures, and their effects on the saccharification potential of rice lignocellulosic biomass. A recombinant inbred lines (RILs) population derived from a cross between the lowland rice variety IR1552 and the upland rice variety Azucena with 271 molecular markers for quantitative trait SNP (QTS) analyses was used. After association analysis of 271 markers for saccharification potential, 1 locus and 4 pairs of epistatic loci were found to contribute to the enzymatic digestibility phenotype, and an inverse relationship between reducing sugar and lignin content in these recombinant inbred lines was identified. As a result of QTS analyses, several cell-wall associated candidate genes are proposed that may be useful for marker-assisted breeding and may aid breeders to produce potential high saccharification rice varieties

Determination of the number of J/ψ events with J/ψ → inclusive decays

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Investigation of the Influence of Deletional and Non-Deletional Hemoglobin H Disease on Pregnancy Outcomes

Kai Sun Zhao,1,&ast; Qiao Ai Pan,2,&ast; Hong Yan Yang,2 Jun You Su,2 Li Deng2 1Department of Obstetrics, The Second Nanning People’s Hospital (The Third Affiliated Hospital of Guangxi Medical University), Nanning, Guangxi, 530031, People’s Republic of China; 2Department of Obstetrics, The Second Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, 530007, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Li Deng; Junyou Su, Department of Obstetrics, The Second Affiliated Hospital of Guangxi Medical University, No. 166, Daxuedong Road, Xixiangtang District, Nanning, Guangxi Zhuang Autonomous Region, People’s Republic of China, Tel +86 13877105871 ; +86 15277199813, Email [email protected]; [email protected]: The study aimed to provide clinical evidence regarding the perinatal management of HbH disease by comparing and analyzing blood routine, anemia characteristics, and their influence on pregnancy outcomes in patients with common deletional and non-deletional HbH disease at various pregnancy stages.Patients and Methods: From May 2017 to October 2023, a comparative analysis was conducted on pregnant women undergoing treatment at the Second Affiliated Hospital of Guangxi Medical University and the Second Nanning People’s Hospital. The study included 42 cases of deletional HbB disease and 32 cases of non-deletional HbH disease. The study assessed blood routine, anemia, and pregnancy outcomes during early and late pregnancy.Results: In the deletional group, there was a significantly higher incidence of moderate anemia during both early and late pregnancy compared to the non-deletional group. Moreover, the deletional group exhibited a significantly lower mean corpuscular volume (MCV) during early and late pregnancy and mean corpuscular hemoglobin (MCH) during late pregnancy, with statistically significant differences (p< 0.05) compared to the non-deletional group. Additionally, the non-deletional group had a significantly higher incidence of postpartum blood transfusion, fetal growth restriction (FGR), and low birth weight (LBW) compared to the deletional group, with a statistically significant difference (p< 0.05).Conclusion: Pregnant patients with alpha-thalassemia HbH disease and non-deletional HbH disease commonly experience moderate anemia, increasing the risk of adverse pregnancy outcomes, particularly in non-deletional HbH disease cases where negative outcomes are more prevalent. It is crucial to enhance perinatal monitoring and intervention for pregnant women with HbH disease, including regular assessment of hemoglobin (Hb) levels, MCV, and MCH, and implementing measures to manage anemia to mitigate adverse pregnancy outcomes effectively.Keywords: hemoglobin H disease, deletional HbH, non-deletional HbH, perinatal care, pregnancy outcome

Higher-order multipole amplitude measurement in ψ ′→γχ c2

Using 106×106 ψ ′ events collected with the BESIII detector at the BEPCII storage ring, the higher-order multipole amplitudes in the radiative transition ψ ′→γχ c2→γπ +π -/γK +K - are measured. A fit to the χ c2 production and decay angular distributions yields M2=0.046±0. 010±0.013 and E3=0.015±0.008±0.018, where the first errors are statistical and the second systematic. Here M2 denotes the normalized magnetic quadrupole amplitude and E3 the normalized electric octupole amplitude. This measurement shows evidence for the existence of the M2 signal with 4.4σ statistical significance and is consistent with the charm quark having no anomalous magnetic moment. © 2011 American Physical Society.published_or_final_versio

Robust nonfullerene solar cells approaching unity external quantum efficiency enabled by suppression of geminate recombination

Nonfullerene solar cells have increased their efficiencies up to 13%, yet quantum efficiencies are still limited to 80%. Here we report efficient nonfullerene solar cells with quantum efficiencies approaching unity. This is achieved with overlapping absorption bands of donor and acceptor that increases the photon absorption strength in the range from about 570 to 700 nm, thus, almost all incident photons are absorbed in the active layer. The charges generated are found to dissociate with negligible geminate recombination losses resulting in a short-circuit current density of 20 mA cm−2 along with open-circuit voltages >1 V, which is remarkable for a 1.6 eV bandgap system. Most importantly, the unique nano-morphology of the donor:acceptor blend results in a substantially improved stability under illumination. Understanding the efficient charge separation in nonfullerene acceptors can pave the way to robust and recombination-free organic solar cells

First observation of the decays χcJ→π0π0π0π0

We present a study of the P-wave spin-triplet charmonium χ cJ decays (J=0, 1, 2) into π0π0π0π0. The analysis is based on 106×106 ψ⊃′ decays recorded with the BESIII detector at the BEPCII electron positron collider. The decay into the π0π0π0π0 hadronic final state is observed for the first time. We measure the branching fractions B(χ c0→π0π0π0π0)=(3.34±0. 06±0.44)×10⊃-3, B(χ c1→π0π0π0π0) =(0.57±0.03±0.08)×10⊃-3, and B(χ c2→π0π0π0π0)=(1.21±0.05±0.16) ×10⊃-3, where the uncertainties are statistical and systematical, respectively. © 2011 American Physical Society.published_or_final_versio

Study of a00(980)-f0(980) mixing

Using samples of 2.25×108 J/ψ events and 1.06×108 ψ ′ events collected with the BES III detector, we study the f 0(980)→a00(980) and a00(980)→f 0(980) transitions in the processes J/ψ→φf 0(980) →φa00(980) and χ c1→π0a00(980)→π0f 0(980), respectively. Evidence for f 0(980)→a00(980) is found with a significance of 3.4σ, while in the case of a00(980)→f 0(980) transition, the significance is 1.9σ. Measurements and upper limits of both branching ratios and mixing intensities are determined. © 2011 American Physical Society.published_or_final_versio