Heat transport in an angular-momentum-conserving lattice.

It is expected that the energy-diffusion propagator in a one-dimensional nonlinear lattice with three conserved quantities: energy, momentum, and stretch, consists of a central heat mode and two sound modes. The heat mode follows a Lévy distribution. Consequently, the heat diffusion is super, i.e., the second moment of the diffusion propagator diverges as t^{ß} with ß>1; and the heat conduction is anomalous, i.e., the heat conductivity is size dependent and diverges with size N by N^{α}, with α>0. In this paper, we study a one-dimensional lattice with two-dimensional transverse motions, in which the total angular momentum also conserves. More importantly, the diffusion of this conserved quantity is ballistic. Surprisingly, the above pictures and the values of the mentioned power exponents keep unchanged. The universality of the scalings is then further extended. On the other hand, the detailed strengths of heat transports are largely enhanced. Such a counterintuitive finding can be explained by the change of the phonon mean-free path of the lattices.

Nonossifying fibroma of the lower femur with genu valgum: a case report.

BACKGROUND: Nonossifying fibroma is common in children and adolescents, and nonossifying fibroma with genu valgum is rare in the clinic. This article evaluated the effectiveness of treatment in a case of nonossifying fibroma of the lower femur with genu valgum. CASE PRESENTATION: A 16-year-old girl complained of pain in the lower part of her right thigh for one year. She was diagnosed as non ossifying fibroma of the right femur with secondary valgus deformity of the right knee, and was treated in our hospital. We performed curettage, bone grafting and internal fixation,and corrected the valgum deformity at the same time. The patient's incision healed well, the pain was disappeared, and the mechanical axis of lower limbs was corrected. No tumor recurrence was found on X- ray examination one year after operation, and the fracture end was healed. The patient could walk normally, and she was satisfied with her limb function. CONCLUSION: Nonossifying fibroma with genu valgum is rare in the clinic. The patient was satisfied with our treatment, which achieved a good curative effect.

Thermalization process in a one-dimensional lattice with two-dimensional motions: The role of angular momentum conservation.

We study the thermalization process in a one-dimensional lattice with two-dimensional motions. The phonon modes in such a lattice consist of two branches. Unlike in general nonlinear Hamiltonian systems, for which the only conserved quantity is the total energy, the total angular momentum J is also conserved in this system. Consequently, the intra- and interbranch energy transports behave significantly differently. For the intrabranch transport, all the existing rules for the one-dimensional systems including the Chirikov overlap criterion apply. As for the interbranch transport, some trivial processes in one-dimensional lattices become nontrivial. During these processes, all the conservation laws can be satisfied exactly; thus the Chirikov criterion does not apply. These processes provide some fast channels for the interbranch transport, although the thermalization cannot be reached through them alone. A system with nonzero-J initial state, however, can never be thermalized to an equipartition state having zero J. Quite counterintuitively, the corresponding asymptotic mode energy distribution greatly concentrates to a few lowest-frequency modes in one branch.

Genome-wide identification of alternative splicing and splicing regulated in immune infiltration in osteosarcoma patients.

Background: Osteosarcoma typically occurs in adolescents, and the survival rate of patients with metastatic and recurrent osteosarcoma remains low. Abnormal regulation of alternative splicing is associated with the development of osteosarcoma. However, there is no genome-wide analysis of the function and regulatory mechanisms of aberrant alternative splicing associated with osteosarcoma. Methods: Published transcriptome data on osteosarcoma (GSE126209) derived from osteosarcoma patient tissue were downloaded. Gene expression profiling by high-throughput sequencing was performed on 9 normal samples and 10 tumor samples for genome-wide identification of osteosarcoma-related alternative splicing events. The potential function of osteosarcoma-associated alternative splicing events was examined by immune infiltration and correlation analysis. Regulation of aberrantly expressed RNA-binding proteins (RBPs) related to alternative splicing in osteosarcoma was clarified by co-expression analysis. Results: A total of 63 alternative splicing events, which are highly credible and dominant, were identified. GO enrichment analysis indicated that alternative splicing may be closely related to the immune response process. Immune infiltration analysis showed significant changes in the percentages of CD8 T cells, resting memory CD4 T cells, activated memory CD4 T cells, monocytes, resting dendritic cells, and activated mast cells in tumors compared to normal tissues, indicating the involvement of these immune cell types in the occurrence of osteosarcoma. Moreover, the analysis identified alternative splicing events that were co-altered with resting memory CD4 T cells, resting dendritic cells, and activated mast cells, events that may be associated with regulation of the osteosarcoma immune microenvironment. In addition, a co-regulatory network (RBP-RAS-immune) of osteosarcoma-associated RBPs with aberrant alternative splicing and altered immune cells was established. These RBPs include NOP58, FAM120C, DYNC1H1, TRAP1, and LMNA, which may serve as molecular targets for osteosarcoma immune regulation. Conclusion: These findings allow us to further understand the causes of osteosarcoma development and provide a new research direction for osteosarcoma immunotherapy or targeted therapy.

Part of speech tagging of grammatical features related to L2 Chinese development: A case analysis of Stanza in the L2 writing context.

Grammatical complexity has received extensive attention in second language acquisition. Although computational tools have been developed to analyze grammatical complexity, most relevant studies investigated this construct in the context of English as a second language. In response to an increasing number of L2 Chinese learners, it is important to extend the investigation of grammatical complexity in L2 Chinese. To promote relevant research, we evaluated the new computational tool, Stanza, on its accuracy of part-of-speech tagging for L2 Chinese writing. We particularly focused on eight grammatical features closely related to L2 Chinese development. Then, we reported the precisions, recalls, and F-scores for the individual grammatical features and offered a qualitative analysis of systematic tagging errors. In terms of the precision, three features have high rates, over 90% (i.e., ba and bei markers, classifiers, -de as noun modifier marker). For recall, four features have high rates, over 90% (i.e., aspect markers, ba and bei markers, classifiers, -de as noun modifier marker). Overall, based on the F-scores, Stanza has a good tagging performance on ba and bei markers, classifiers, and -de as a noun modifier marker. This evaluation provides research implications for scholars who plan to use this computational tool to study L2 Chinese development in second language acquisition or applied linguistics in general.

Follow-up of biological reconstruction of epiphysis preserving osteosarcoma around the knee in children: A retrospective cohort study.

Limb salvage treatment for malignant bone tumors in children includes prosthetic and biological reconstruction. Early function following prosthesis reconstruction is satisfactory; however, there are several complications. Biological reconstruction is another way to treat bone defects. We evaluated the effectiveness of reconstruction of bone defects by liquid nitrogen inactivation of autologous bone with preserving epiphysis in 5 cases of periarticular osteosarcoma of the knee. We retrospectively selected 5 patients with articular osteosarcoma of the knee who underwent epiphyseal-preserving biological reconstruction in our department between January 2019 and January 2020. Femur involvement occurred in 2 cases and tibia involvement occurred in 3 cases, with an average defect of 18 cm (12-30 cm). The 2 patients with femur involvement were treated with inactivated autologous bone by liquid nitrogen with vascularized fibula transplantation. Among the patients with tibia involvement, 2 were treated with inactivated autologous bone with ipsilateral vascularized fibula transplantation and 1 was treated with autologous inactivated bone with contralateral vascularized fibula transplantation. Bone healing was evaluated by regular X-ray examination. At the end of the follow-up, lower limb length, knee flexion, and extension function were evaluated. Patients were followed up for 24 to 36 months. Average bone-healing time was 5.2 months (3-8 months). All patients achieved bone healing with no tumor recurrence and no distant metastasis and all patients survived. The lengths of both lower limbs were equal in 2 cases, with shortening by ≤1 cm in 1 case and shortening by 2 cm in 1 case. Knee flexion was >90° in 4 cases and between 50 and 60° in 1 case. The Muscle and Skeletal Tumor Society score was 24.2 (range 20-26). Inactivation of autogenous bone with the epiphysis preserved by liquid nitrogen combined with vascularized fibula reconstruction for periarticular osteosarcoma of the knee in children is safe and effective. This technique supports bone healing. Postoperative limb length and function, and short-term effects were satisfactory.

Energy diffusion in two-dimensional momentum-conserving nonlinear lattices: Lévy walk and renormalized phonon.

The energy diffusion process in a few two-dimensional Fermi-Pasta-Ulam-type lattices is numerically simulated via the equilibrium local energy spatiotemporal correlation. Just as the nonlinear fluctuating hydrodynamic theory suggested, the diffusion propagator consists of a bell-shaped central heat mode and a sound mode extending with a constant speed. The profiles of the heat and sound modes satisfy the scaling properties from a random-walk-with-velocity-fluctuation process very well. An effective phonon approach is proposed, which expects the frequencies of renormalized phonons as well as the sound speed with quite good accuracy. Since many existing analytical and numerical studies indicate that heat conduction in such two-dimensional momentum-conserving lattices is divergent and the thermal conductivity κ increases logarithmically with lattice length, it is expected that the mean-square displacement of energy diffusion grows as tlnt. Discrepancies, however, are noticeably observed.

Correlation functions and their universal connection during an extremely slow equilibration process.

We study the equilibration process of a one-dimensional lattice with transverse motions and external magnetic field. Starting from certain initial states, the system commonly reaches a metastable transient state shortly and then stays there for an extremely long time before it finally arrives in the ergodic equilibrium state. The relaxation time T_{eq} diverges even much more rapidly than exponential, which, compared with the widely reported power-law or even exponential divergence in many other systems, implies much higher stability of the transient state. Two correlation functions, the spatiotemporal correlation of the local energy and the autocorrelation of global heat current, are studied in both the metastable transient and the final equilibrium states. It is revealed that the correlations behave entirely differently in the two different states. In the former case they suggest normal heat diffusion and normal heat conduction; whereas in the latter one they indicate super heat diffusion and anomalous heat conduction. More importantly, we confirm that a general relation which connects the two correlations keeps valid not only in the equilibrium state but in the metastable transient state as well. The universality of the connection is, thus, extended.

Resection and reconstruction of huge tumors in the chest wall.

OBJECTIVE: To evaluate the experience and effects of resection and reconstruction of 4 cases of huge tumors in the chest wall. METHODS: The clinical data of 4 patients with huge tumors in the chest wall from July 2015 to January 2020 were collected and analyzed. There were 2 males and 2 females.Chondrosarcoma was diagnosed in 2 cases, giant cell tumor was diagnosed in 1 case,and metastasis from breast cancer was diagnosed in 1 case.All patients underwent extensive tumor resection and had thoracic exposure after tumor resection.Two patients underwent reconstruction with mesh and titanium mesh, and the incision was closed directly.The third patient underwent reconstruction with mesh and latissimus dorsi flap,and the fourth patient underwent reconstruction with mesh,titanium mesh and latissimus dorsi flap. RESULT: One patient had incision infection after operation,which resolved after debridement.All patients were followed up for 2-6 years, no tumor recurrence or metastasis was noted during follow-up.None of patients had abnormal breathing, dyspnea or other physical discomfort. CONCLUSION: It is difficult to resect the huge tumors in the chest wall,and it is more reasonable and safer to choose a reconstruction method using mesh and titanium mesh.The latissimus dorsi flap can achieve good results in repairing soft tissue defects.Close perioperative management and multidisciplinary team discussions can help to achieve better curative effects.

METTL3 stabilizes HDAC5 mRNA in an m6A-dependent manner to facilitate malignant proliferation of osteosarcoma cells.

Osteosarcoma (OS) is a prevalent primary bone sarcoma. Methyltransferase-like 3 (METTL3) is dysregulated in human malignancies. This study explored the mechanism of METTL3 in OS cell proliferation. Our results demonstrated that METTL3 was highly expressed in OS, and correlated with the tumor size, clinical stage, and distant metastasis of OS patients. Higher METTL3 expression indicated poorer prognosis. METTL3 silencing inhibited the malignant proliferation of OS cells, while METTL3 overexpression led to an opposite trend. METTL3 upregulated histone deacetylase 5 (HDAC5) expression in OS cells by increasing the m6A level. HDAC5 reduced the enrichment of H3K9/K14ac on miR-142 promoter, thus suppressing miR-142-5p expression and upregulating armadillo-repeat-containing 8 (ARMC8) level. HDAC5 overexpression or miR-142-5p silencing attenuated the inhibitory effect of METTL3 silencing on OS cell proliferation. Xenograft tumor experiment in nude mice confirmed that METTL3 silencing repressed OS cell proliferation in vivo via the HDAC5/miR-142-5p/ARMC8 axis. Collectively, METTL3-mediated m6A modification facilitated OS cell proliferation via the HDAC5/miR-142-5p/ARMC8 axis.

[Resveratrol reduces apoptosis of mouse RAW264.7 macrophage via down-regulating HIF-1α].

Objective To investigate the protective effect of resveratrol (Res) against mouse RAW264.7 macrophage injury induced by cobalt chloride (CoCl2) and its mechanism. Methods Macrophages were divided into control group, CoCl2 group and Res pretreatment group. CoCl2 group was treated with 500 µmol/L CoCl2 for 8 hours, and Res pretreatment group was pretreated with 40 µmol/L Res for 2 hours followed by 500 µmol/L CoCl2 treatment for 8 hours. The cell vitality and apoptotic rate in every group were detected by CCK-8 assay and flow cytometry. The distributions of caspase-3 and hypoxia-inducible factor 1 alpha (HIF-1α), as well as the influences of CoCl2 and Res on their expression were detected by immunofluorescence cytochemistry. The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in every group were measured by the corresponding kits. The expression levels of Bcl2, BAX, c-caspase-3 and HIF-1α in every group were observed by Western blot analysis. Results Compared with the CoCl2 group, pretreatment with Res increased cell vitality, decreased apoptosis, enhanced the activity of SOD, and reduced the level of MDA. The caspase-3 was mainly distributed in the cytoplasm, and HIF-1α was mainly distributed on the nucleus. Compared with the CoCl2 group, Res up-regulated the expression of Bcl2 and down-regulated the expression of BAX, cleaved caspase-3 and HIF-1α. Conclusion Res can decrease apoptosis in macrophages, which may occur via reducing the accumulation of intracellular reactive oxygen species, enhancing cell antioxidant capacity, and down-regulating the expression of HIF-1α on cells.