866 research outputs found
Residue theorem and summing over Kaluza-Klein excitations
Applying the equations of motion together with corresponding boundary
conditions of bulk profiles at infrared and ultraviolet branes, we verify some
lemmas on the eigenvalues of Kaluze-Klein modes in framework of warped extra
dimension with the custodial symmetry . Using the lemmas and performing properly
analytic extensions of bulk profiles, we present the sufficient condition for a
convergent series of Kaluze-Klein excitations and sum over the series through
the residue theorem. The method can also be applied to sum over the infinite
series of Kaluze-Klein excitations in unified extra dimension. Additional, we
analyze the possible connection between the propagators in five dimensional
full theory and the product of bulk profiles with corresponding propagators of
exciting Kaluze-Klein modes in four dimensional effective theory, and recover
some relations presented in literature for warped and unified extra dimensions
respectively. As an example, we demonstrate that the corrections from neutral
Higgs to the Wilson coefficients of relevant operators for contain the suppression factor comparing
with that from other sectors, thus can be neglected safely.Comment: 44 pages, no figur
A Unified Continual Learning Framework with General Parameter-Efficient Tuning
The "pre-training downstream adaptation" presents both new
opportunities and challenges for Continual Learning (CL). Although the recent
state-of-the-art in CL is achieved through Parameter-Efficient-Tuning (PET)
adaptation paradigm, only prompt has been explored, limiting its application to
Transformers only. In this paper, we position prompting as one instantiation of
PET, and propose a unified CL framework with general PET, dubbed as
Learning-Accumulation-Ensemble (LAE). PET, e.g., using Adapter, LoRA, or
Prefix, can adapt a pre-trained model to downstream tasks with fewer parameters
and resources. Given a PET method, our LAE framework incorporates it for CL
with three novel designs. 1) Learning: the pre-trained model adapts to the new
task by tuning an online PET module, along with our adaptation speed
calibration to align different PET modules, 2) Accumulation: the task-specific
knowledge learned by the online PET module is accumulated into an offline PET
module through momentum update, 3) Ensemble: During inference, we respectively
construct two experts with online/offline PET modules (which are favored by the
novel/historical tasks) for prediction ensemble. We show that LAE is compatible
with a battery of PET methods and gains strong CL capability. For example, LAE
with Adaptor PET surpasses the prior state-of-the-art by 1.3% and 3.6% in
last-incremental accuracy on CIFAR100 and ImageNet-R datasets, respectively.
Code is available at \url{https://github.com/gqk/LAE}.Comment: Accepted to ICCV 202
Reconstruction of Hematopoietic Inductive Microenvironment after Transplantation of VCAM-1-Modified Human Umbilical Cord Blood Stromal Cells
The hematopoietic inductive microenvironment (HIM) is where hematopoietic stem/progenitor cells grow and develop. Hematopoietic stromal cells were the key components of the HIM. In our previous study, we had successfully cultured and isolated human cord blood–derived stromal cells (HUCBSCs) and demonstrated that they could secret hemopoietic growth factors such as GM-CSF, TPO, and SCF. However, it is still controversial whether HUCBSCs can be used for reconstruction of HIM. In this study, we first established a co-culture system of HUCBSCs and cord blood CD34+ cells and then determined that using HUCBSCs as the adherent layer had significantly more newly formed colonies of each hematopoietic lineage than the control group, indicating that HUCBSCs had the ability to promote the proliferation of hematopoietic stem cells/progenitor cells. Furthermore, the number of colonies was significantly higher in vascular cell adhesion molecule-1 (VCAM-1)-modified HUCBSCs, suggesting that the ability of HUCBSCs in promoting the proliferation of hematopoietic stem cells/progenitor cells was further enhanced after having been modified with VCAM-1. Next, HUCBSCs were infused into a radiation-damaged animal model, in which the recovery of hematopoiesis was observed. The results demonstrate that the transplanted HUCBSCs were “homed in” to bone marrow and played roles in promoting the recovery of irradiation-induced hematopoietic damage and repairing HIM. Compared with the control group, the HUCBSC group had significantly superior effectiveness in terms of the recovery time for hemogram and myelogram, CFU-F, CFU-GM, BFU-E, and CFU-Meg. Such differences were even more significant in VCAM-1-modified HUCBSCs group. We suggest that HUCBSCs are able to restore the functions of HIM and promote the recovery of radiation-induced hematopoietic damage. VCAM-1 plays an important role in supporting the repair of HIM damage
A few recent developments in fluidized bed technology applications for fuel conversion
In recent years, the process concepts based on two-stage and dual bed have been widely adopted in developing fuel conversion technologies including pyrolysis, combustion, gasification and catalytic cracking. These provide indeed advantages of, for example, easy operation and control, poly-generation of products, and high efficiency in elimination of undesirable product or pollutants. The so-called micro fluidized bed analyzer (MFBRA) has been newly developed to measure reaction rates at arbitrary temperatures, giving a great support to fundamental research and technology developments for fuel conversion. This report intends to summarize the involved new concepts, major fundamental understandings, pilot test and/or industrial demonstrations of a few newly developed fuel conversion technologies. Concretely, it will report fluidized bed two-stage gasification (FBTSG), dual fluidized bed pyrolysis combustion (DBPC), fluidized bed cracking gasification (FBCG) and MFBRA.
The FBTSG technology separates fuel pyrolysis in a FB pyrolyzer and char gasification in a transport bed gasifier. The latter enables high-temperature tar cracking under catalysis of char to enable remarkably low tar content in the produced gas [1]. For fuel with high contents of water and nitrogen, the DBPC technology first removes fuel water and most fuel volatile in a pyrolyzer. This, on the one hand, ensures stable combustion of the fuel, and on the other hand facilitates NOx reduction by char and pyrolysis gas [2]. The FBCG technology separates the catalytic cracking of heavy feedstock for liquid and the gasification of char, the cokes formed on the catalyst surface, to produce syngas and also to regenerate the catalyst. By using micro fluidized bed, the MFBRA is newly developed to enable the on-line pulse feeding and rapid heating of particle reactant. It effectively suppresses the interfacial diffusion limitation and minimizes the intra-particle diffusion [3]. Thus, MFBRA provides isothermal reaction analysis in comparison with that in TGA based on programmed heating.
REFERENCES
1. X. Zeng, et al. Pilot verification of a low-tar two-stage coal gasification process with a FB pyrolyzer and fixed bed gasifier. Applied Energy, 115, 9–16, 2014.
2. P. Dagaut, et al. Experiments and kinetic modeling study of NO-reburning by gases from biomass pyrolysis in a JSR. Energy & Fuels, 17(3), 608-613, 2003.
3. J. Yu, et al. Kinetics and mechanism of solid reactions in a micro fluidized bed reactor. AIChE Journal, 56, 2905-2912, 2010
Synthesis and activity study of novel N,N-diphenylurea derivatives as IDO1 inhibitors
Indoleamine 2,3-dioxygenase 1 (IDO1) has attracted much attention in the field of cancer immunotherapy as an immunomodulatory enzyme. To identify potential IDO1 inhibitors, a novel series of compounds with N,N-diphenylurea and triazole structures were synthesized. The designed compounds underwent organic synthesis, and subsequent enzymatic activity experiments targeting IDO1 confirmed their activity at the molecular level. These experiments provided validation for the efficacy of the designed compounds in inhibiting IDO1, compound 3g exhibited an IC50 value of 1.73 ± 0.97 μM. Further molecular docking study further explained the binding mode and reaction potential of compound 3g with IDO1. Our research has resulted in a series of novel IDO1 inhibitors, which is beneficial to the development of drugs targeting IDO1 in numerous cancer diseases
Two‐Dimensional Design Strategy to Construct Smart Fluorescent Probes for the Precise Tracking of Senescence
The tracking of cellular senescence usually depends on the detection of senescence‐associated β‐galactosidase (SA‐β‐gal). Previous probes for SA‐β‐gal with this purpose only cover a single dimension: the accumulation of this enzyme in lysosomes. However, this is insufficient to determine the destiny of senescence because endogenous β‐gal enriched in lysosomes is not only related to senescence, but also to some other physiological processes. To address this issue, we introduce our fluorescent probes including a second dimension: lysosomal pH, since de‐acidification is a unique feature of the lysosomes in senescent cells. With this novel design, our probes achieved excellent discrimination of SA‐β‐gal from cancer‐associated β‐gal, which enables them to track cellular senescence as well as tissue aging more precisely. Our crystal structures of a model enzyme E. coli β‐gal mutant (E537Q) complexed with each probe further revealed the structural basis for probe recognition.<br/
Neurosurgical interventions for patients with nasopharyngeal carcinoma: a single institution experience
BACKGROUND: Nasopharyngeal carcinoma (NPC) is a frequent head and neck cancer in southern China and Southeast Asia. The majority of NPC patients are managed by radiation oncologists, medical oncologists and head and neck surgeons. Actually, neurosurgical interventions are warranted under specific circumstances. In this article, we described our experience as neurosurgeons in the management of NPC patients. METHODS: Medical records of NPC patients who received neurosurgical procedure at Sun Yat-sen University Cancer Center were reviewed. RESULTS: Twenty-seven patients were identified. Among 27 cases, neurosurgical procedures were performed in 18 (66.7%) with radiation-induced temporal necrosis, 2 (7.4%) with radiation-induced sarcoma, 4 (14.8%) with synchronous NPC with primary brain tumors, 2 (7.4%) with recurrent NPC involving skull base, and 1 (3.7%) with metachronous skull eosinophilic granuloma, respectively. The diagnosis is challenging in specific cases and initial misdiagnoses were found in 6 (22.2%) patients. CONCLUSIONS: For NPC patients with intracranial or skull lesions, the initial diagnosis can be occasionally difficult because of the presence or a history of NPC and related treatment. Unawareness of these entities can result in misdiagnosis and subsequent improper treatment. Neurosurgical interventions are necessary for the diagnosis and treatment for these patients
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