69 research outputs found
Time-frequency analyses of blasting vibration signals in single-hole blasting model experiments
With common horseshoe cavern in underground engineering as the prototype, three single-hole blasting model experiments have been carried out. And coupled SPH-FEM approach is adopted for analyzing the limit effect of pre-excavated horseshoe cavern on blasting crater. During the experiment, the blasting vibration signals on the top surface of cemented sand model have been recorded. Then Hilbert-Huang transform has been applied to analyzing the time-frequency characteristics of recorded blasting vibration signals. Both experiment results and numerical cases indicate that the range of blasting crater is controlled effectively by pre-excavating horseshoe cavern, and the limit effect of pre-excavating on blasting crater has a close connection with its length. Moreover, the 50 mm pre-excavated horseshoe cavern presents an amplification effect in blasting vibration effect both along the blasthole direction and perpendicular to the blasthole direction, and it also demonstrates a weaken effect in the main blasting vibration frequency of vertical blasting vibration signal. HHT analyses of vertical blasting vibration signals show that single-hole blasting vibration signals present a centralized distribution in time domain and an uneven distribution in frequency domain. The dominant energy of blasting vibration signal is distributed in several IMF components, where main blasting vibration frequency locates. When cutting the charge, the blasting vibration effect will be reduced, while the main blasting vibration frequency of blasting vibration signal will be increased
Hard rock deep hole cutting blasting technology in vertical shaft freezing bedrock section construction
Using the traditional cutting blasting technology in vertical shaft construction has some features, e.g. slows driving speed, gangue with large volume and throwing high. Moreover, large explosive charge initiation has a serious influence on freezing pipes and freezing wall. In this study, the periphery hole charge and charge structure was optimized, and the blasting model of the bedrock vertical shaft section was established by using the ANSYS/LS-DYNA numerical simulation software. In addition, stress concentration of the large diameter empty hole and its influence of blasting efficiency in blasting were analyzed. The field experiment was conducted to verify the blasting results. The results show that using large diameter empty hole blasting technology in vertical shaft construction of frozen hard rock section can significantly improve the speed of vertical shaft construction, obtain the excellent blasting effect and guarantee the safety of freezing pipes and freezing wall
Hard rock deep hole cutting blasting technology in vertical shaft freezing bedrock section construction
Using the traditional cutting blasting technology in vertical shaft construction has some features, e.g. slows driving speed, gangue with large volume and throwing high. Moreover, large explosive charge initiation has a serious influence on freezing pipes and freezing wall. In this study, the periphery hole charge and charge structure was optimized, and the blasting model of the bedrock vertical shaft section was established by using the ANSYS/LS-DYNA numerical simulation software. In addition, stress concentration of the large diameter empty hole and its influence of blasting efficiency in blasting were analyzed. The field experiment was conducted to verify the blasting results. The results show that using large diameter empty hole blasting technology in vertical shaft construction of frozen hard rock section can significantly improve the speed of vertical shaft construction, obtain the excellent blasting effect and guarantee the safety of freezing pipes and freezing wall
XGNN: Towards Model-Level Explanations of Graph Neural Networks
Graphs neural networks (GNNs) learn node features by aggregating and
combining neighbor information, which have achieved promising performance on
many graph tasks. However, GNNs are mostly treated as black-boxes and lack
human intelligible explanations. Thus, they cannot be fully trusted and used in
certain application domains if GNN models cannot be explained. In this work, we
propose a novel approach, known as XGNN, to interpret GNNs at the model-level.
Our approach can provide high-level insights and generic understanding of how
GNNs work. In particular, we propose to explain GNNs by training a graph
generator so that the generated graph patterns maximize a certain prediction of
the model.We formulate the graph generation as a reinforcement learning task,
where for each step, the graph generator predicts how to add an edge into the
current graph. The graph generator is trained via a policy gradient method
based on information from the trained GNNs. In addition, we incorporate several
graph rules to encourage the generated graphs to be valid. Experimental results
on both synthetic and real-world datasets show that our proposed methods help
understand and verify the trained GNNs. Furthermore, our experimental results
indicate that the generated graphs can provide guidance on how to improve the
trained GNNs
Pressure-induced superconductivity in kagome single crystal Pd3P2S8
Kagome lattice offers unique opportunities for the exploration of unusual
quantum states of correlated electrons. Here, we report on the observation of
superconductivity in a kagome single crystal Pd3P2S8 when a semiconducting to
metallic transition is driven by pressure. High-pressure resistance
measurements show that the metallization and superconductivity are
simultaneously observed at about 11 GPa. With increasing pressure, the
superconducting critical temperature Tc is monotonously enhanced from 2.6 K to
a maximum 7.7 K at ~52 GPa. Interestingly, superconductivity retains when the
pressure is fully released. Synchrotron XRD and Raman experiments consistently
evidence that the emergence of superconductivity is accompanied with an
amorphization and the retainability of superconductivity upon decompression can
be attributed to the irreversibility of the amorphization
A prospective phase II study of L-asparaginase- CHOP plus radiation in newly diagnosed extranodal NK/T-cell lymphoma, nasal type
Purpose: To explore the efficacy and safety of L-asparaginase in newly-diagnosed extranodal nature killer (NK)/T -cell lymphoma (ENKTL), we conducted a prospective phase II study of L-asparaginase, cyclophosphamide, vincristine, doxorubicin and dexamethasone (CHOP-L) regimen in combination with radiotherapy. Patients and methods: Patients with newly diagnosed ENKTL and an ECOG performance status of 0 to 2 were eligible for enrollment. Treatment included 6-8 cycles of CHOP-L (cyclophosphamide, 750 mg/m(2) day 1; vincristine, 1.4 mg/m(2) day 1 (maximal dose 2 mg), doxorubicin 50 mg/m(2) day 1; dexamethasone 10 mg days 1-8; L-asparaginase 6000 u/m(2) days 2-8). Radiotherapy was scheduled after 4-6 cycles of CHOP-L regimen, depending on stage and primary anatomic site. The primary endpoint was complete response (CR) rate. Results: A total of 38 eligible patients were enrolled. The median age was 40.5 years (range, 15 to 71 years). Their clinical characteristics were male to female ratio, 24: 14; Ann Arbor stage I, 20; II, 11; III, 3; IV, 4. CR and overall response rates were 81.6% (95% CI, 69.3% to 93.9%) and 84.2%, respectively. With a median follow-up of 25 months, the 2-year overall survival, progression-free survival and disease-free survival rates were 80.1% (95% CI, 73.3% to 86.9%), 81% (95% CI, 74.5% to 87.5%) and 93.6% (95% CI, 89.3% to 97.9%), respectively. The major adverse events were myelosuppression, liver dysfunction, and digestive tract toxicities. Grade 3 to 4 leukopenia and neutropenia were 76.3% and 84.2%, respectively. No treatment-related death was observed. Conclusion: CHOP-L chemotherapy in combination with radiotherapy is a safe and highly effective treatment for newly diagnosed ENKTL.OncologyHematologySCI(E)9ARTICLEnull
Nanoscale probing of electron-regulated structural transitions in silk proteins by near-field IR imaging and nano-spectroscopy
Silk protein fibres produced by silkworms and spiders are renowned for their unparalleled mechanical strength and extensibility arising from their high-β-sheet crystal contents as natural materials. Investigation of β-sheet-oriented conformational transitions in silk proteins at the nanoscale remains a challenge using conventional imaging techniques given their limitations in chemical sensitivity or limited spatial resolution. Here, we report on electron-regulated nanoscale polymorphic transitions in silk proteins revealed by near-field infrared imaging and nano-spectroscopy at resolutions approaching the molecular level. The ability to locally probe nanoscale protein structural transitions combined with nanometre-precision electron-beam lithography offers us the capability to finely control the structure of silk proteins in two and three dimensions. Our work paves the way for unlocking essential nanoscopic protein structures and critical conditions for electron-induced conformational transitions, offering new rules to design protein-based nanoarchitectures.National Science Foundation (U.S.) (1563422)National Science Foundation (U.S.) (1562915
Positron-emission tomography–based staging reduces the prognostic impact of early disease progression in patients with follicular lymphoma
Background: Previous studies reported that early progression of disease (POD) after initial therapy predicted poor overall survival (OS) in patients with follicular lymphoma (FL). Here, we investigated whether pre-treatment imaging modality had an impact on prognostic significance of POD. Methods: In this retrospective study, we identified 1088 patients with grade I–IIIA FL; of whom, 238 patients with stage II–IV disease were initially treated with rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP), and 346 patients were treated with rituximab-based chemotherapy. Patients (N = 484) from the FOLL05 study served as an independent validation cohort. We risk-stratified patients based on pre-treatment radiographic imaging (positron-emission tomography [PET] versus computed tomography [CT]) and early POD status using event-defining and landmark analyses. A competing risk analysis evaluated the association between early POD and histologic transformation. Results: In the discovery cohort, patients with POD within 24 months (PFS24) of initiating R-CHOP therapy had a 5-year OS of 57.6% for CT-staged patients compared with 70.6% for PET-staged patients. In the validation cohort, the 5-year OS for patients with early POD was 53.9% and 100% in CT- and PET-staged patients, respectively. The risk of histologic transformation in patients whose disease progressed within one year of initiating therapy was higher in CT-staged patients than in PET-staged patients (16.7% versus 6.3%, respectively), which was associated with a 9.7-fold higher risk of death. Conclusion: In FL, pre-treatment PET staging reduced the prognostic impact of early POD compared with CT staging. Patients with early POD and no histologic transformation have an extended OS with standard therapy
Antitumor activity and safety of camrelizumab combined with apatinib in patients with relapsed or refractory peripheral T-cell lymphoma: An open-label, multicenter, phase II study
IntroductionThe treatment for relapsed/refractory peripheral T-cell lymphoma (r/r PTCL) is suboptimal. This open-label, multicenter, single-arm study aimed to investigate the antitumor activity and safety of camrelizumab (a PD-1 blockade) plus apatinib (an antiangiogenic agent) for patients with r/r PTCL.MethodsEligible patients with r/r PTCL were enrolled and received camrelizumab 200 mg intravenously every 2 weeks and apatinib 500 or 250 mg orally once daily, 4 weeks as a cycle. The primary endpoint was overall response rate (ORR).ResultsA total of 20 patients were enrolled and received study medications in the study, with a median number of prior treatment line of 3 (range 1-6). At the cutoff date of March 4, 2022, the median follow-up was 27.2 months (range: 0.5-39.9), and three patients remained on treatment. Six patients had early discontinuation without tumor response evaluation. For all patients, the ORR was 30% (6/20) (95% confidence interval [CI], 11.9% to 54.3%), with two patients (10%) achieving complete response. The median progression-free survival (PFS) and median overall survival for all patients were 5.6 months (95% CI, 1.8 to not reached) and 16.7 months (95% CI, 2.8 to not reached), respectively. Patients with PD-L1 expression ≥50% (3 patients) had a numerically higher ORR and longer median PFS than those with PD-L1 expression < 50% (5 patients). The most commonly reported grade 3 or higher adverse events were hyperlipidemia (15%), hypokalemia (15%) and anemia (15%). No treatment-related deaths occurred.DiscussionIn this study, PD-1 inhibitors plus low-dose antiangiogenic drugs presented preliminary antitumor activity and manageable toxicity in patients with r/r PTCL
Interpreting Deep Learning-Based Networking Systems
While many deep learning (DL)-based networking systems have demonstrated
superior performance, the underlying Deep Neural Networks (DNNs) remain
blackboxes and stay uninterpretable for network operators. The lack of
interpretability makes DL-based networking systems prohibitive to deploy in
practice. In this paper, we propose Metis, a framework that provides
interpretability for two general categories of networking problems spanning
local and global control. Accordingly, Metis introduces two different
interpretation methods based on decision tree and hypergraph, where it converts
DNN policies to interpretable rule-based controllers and highlight critical
components based on analysis over hypergraph. We evaluate Metis over several
state-of-the-art DL-based networking systems and show that Metis provides
human-readable interpretations while preserving nearly no degradation in
performance. We further present four concrete use cases of Metis, showcasing
how Metis helps network operators to design, debug, deploy, and ad-hoc adjust
DL-based networking systems.Comment: To appear at ACM SIGCOMM 202
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