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1.
Proc Natl Acad Sci U S A ; 120(44): e2312538120, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37871224

RESUMO

Experiments are performed on micron-scale single-crystal prototypical structural elements experiencing combined torsion and bending to gather data on their load-carrying capacity in the range of size and strain relevant to micron-scale structures for which little data are available. The observed strengthening dependence on size for the structural elements is in general accord with trends inferred from prior tests such as indentation and pure torsion. In addition, the experiments systematically reveal the strengthening size-dependence of structural elements whose surface has been passivated by a very thin Cr coating, an effect shown to have substantial strengthening potential. A state-of-the-art strain gradient plasticity theory is used to analyze the structural elements over the entire range of size and loading. While the computed trends replicate the experimental trends with reasonable fidelity, the predictive exercise, which is representative of those that will be required in micron-scale structural analysis, brings to light constitutive and computational issues which will have to be addressed before micron-scale plasticity theory can serve as effectively at the micron scale as conventional plasticity does at larger scales.

2.
Zhonghua Wei Chang Wai Ke Za Zhi ; 26(7): 707-712, 2023 Jul 25.
Artigo em Chinês | MEDLINE | ID: mdl-37583030

RESUMO

In the past decade, the concept of membrane anatomy has been gradually applied in gastric cancer surgery. Based on this theory, D2 lymphadenectomy plus complete mesogastric excision (D2+CME) has been proposed, which has been demonstrated to significantly reduce intraoperative bleeding and intraperitoneal free cancer cells during surgery, decrease surgical complications, and improve survival. These results indicate that membrane anatomy is feasible and efficacious in gastric cancer surgery. In this review, we will describe the important contents of membrane anatomy, including "Metastasis V"(2013, 2015), proximal segmentation of dorsal mesogastrium (2015), D2+CME procedure (2016), "cancer leak"(2018), and surgical outcomes of D2+CME (2022).


Assuntos
Laparoscopia , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/patologia , Gastrectomia/métodos , Laparoscopia/métodos , Excisão de Linfonodo/métodos , Mesentério/cirurgia
3.
Nanoscale ; 15(31): 13086-13093, 2023 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-37498524

RESUMO

We report the observation of Kirkendall voids at the epitaxial titanium nitride (TiN)/magnesium oxide(MgO)(001) interface. While epitaxial growth of TiN on MgO has been known for years, many reports show a perfectly sharp epitaxial interface. Because TiN is a prototypical diffusion barrier material, observing the consequence of rapid diffusion at a TiN interface is interesting. Structural characterization of the interface using X-ray diffraction and electron microscopy confirms the diffuse nature of the interface. Rectangular voids that form at the TiN/MgO(001) interface and extend into both TiN and MgO result from a large chemical potential gradient at the interface, which contributes a strong chemical driving force for diffusion. The spatial localization of the observed voids is limited to within ∼10 nm from the interface, consistent with a chemical potential gradient driving force. A composition gradient on the nanometer scale is also observed. Observation of Kirkendall voids at this nitride/oxide interface suggests possibilities for engineering oxygen and nitrogen vacancies at thin film interfaces.

4.
Nanoscale Horiz ; 8(5): 674-684, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-36912611

RESUMO

We report the growth of epitaxial wurtzite AlScN thin films on Si (111) substrates with a wide range of Sc concentrations using ultra-high vacuum reactive sputtering. Sc alloying in AlN enhances piezoelectricity and induces ferroelectricity, and epitaxial thin films facilitate systematic structure-based investigations of this important and emerging class of materials. Two main effects are observed as a function of increasing Sc concentration. First, increasing crystalline disorder is observed together with a structural transition from wurtzite to rocksalt at ∼30 at% Sc. Second, nanoscale compositional segregation consistent with spinodal decomposition occurs at intermediate compositions, before the wurtzite to rocksalt phase boundary is reached. Lamellar features arising from composition fluctuations are correlated with polarization domains in AlScN, suggesting that composition segregation can influence ferroelectric properties. The present results provide a route to the creation of single crystal AlScN films on Si (111), as well as a means for self-assembled composition modulation.

5.
Int J Mech Sci ; 1722020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-34140747

RESUMO

Direct replication of microscale patterns onto metal surfaces by compression molding with patterned dies is used to fabricate metal-based structures for microsystem applications. Micron scale plasticity governs both the mechanical molding response and the geometric fidelity of replicated patterns. Microscale molding replication offers a technologically relevant example in which various plasticity size effects manifest themselves and control the effectiveness of the fabrication process. Microscale compression molding of a single-crystal Al specimen was studied by combining experimentation with conventional and strain gradient plasticity finite element simulations. In the single-punch molding configuration, single rectangular punches with different widths and lengths were used. In the double-punch configuration, two identically-dimensioned rectangular punches with a spacing in between were used. Under single-punch molding at the micron scale, both the absolute punch width as well as the length-to-width ratio affected the characteristic molding pressure. Under double-punch molding, both the measured characteristic molding pressure and the material flow to fill the gap between the two rectangular punches exhibited a significant dependence on the spacing to punch-width ratio and-when this ratio was fixed-on the absolute spacing between punches. The present study elucidates the impact of plasticity size effects on the efficacy of pattern replication by molding at the micron scale.

7.
Zhonghua Wei Chang Wai Ke Za Zhi ; 22(4): 349-356, 2019 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-31054549

RESUMO

Objective: To evaluate the safety and preliminary efficacy of total neoadjuvant therapy (TNT) in patients with locally advanced rectal cancer (LARC) with high risk factors. Methods: Data of 101 patients who were diagnosed with stage II-III rectal cancer with high risk factors and received TNT between March 2015 and January 2018 at West China Hospital of Sichuan University were analyzed retrospectively. Inclusion criteria: (1) patients were diagnosed with stage II-III rectal cancer by high-resolution MRI combined with CT and endorectal ultrasound; (2) at least one high risk factor: cT4a, cT4b, cN2, EMVI+, CRM+ and lateral lymph node+; (3) distance from tumor to anal verge was within 15 cm; (4) Eastern Collaborative Oncology Group (ECOG) performance status score was 0-1; bone marrow function, liver function and kidney function were suitable for chemoradiotherapy; (5) patients were treated with TNT strategy; (6) the follow-up data and postoperative pathological data were complete. Patients with previous rectal cancer surgery (except prophylactic colostomy), pelvic radiotherapy, and systemic chemotherapy, those with distant metastases, those without neoadjuvant radiotherapy, those receiving less than 4 cycles of neoadjuvant chemotherapy were excluded. The regimen of TNT: 3 cycles of induction CAPOX (oxaliplatin plus capecitabine) were followed by pelvic radiotherapy and concurrent CAPOX, then 3 cycles of consolidation CAPOX were delivered after radiotherapy. Total mesorectal resection (TME) or watch-and-wait strategy was selected according to the therapeutic effect and patients' wishes. Short-term efficacy, including tumor regression grade (TRG), pathological complete response (pCR), clinical complete response (cCR), postoperative complications within 30 days of surgery, and adverse events (AE) to radiotherapy and chemotherapy (measured using CTCAE 4.0) was analyzed. Results: The 101 patients included 68 males (67.3%) and 33 females (32.7%) with a median age of 54 years. The proportion of patients with cT4a, cT4b, cN2 and enlarged lateral lymph node was 13.9%, 29.7%, 56.4% and 43.6%, respectively. The mean cycle of neoadjuvant chemotherapy was 6.0±1.3. Seventy-five patients (74.3%) received at least 6 cycles of neoadjuvant chemotherapy and 100 (99.0%) completed radiotherapy. The mean cycle of induction and consolidation chemotherapy was 2.0±0.9 and 2.8±1.0 respectively. Most common grade 3 AE was leucopenia (n=13, 12.9%) and thrombocytopenia (n=7, 6.9%). Grade 3 diarrhea and radiation dermatitis were observed in 5 cases (5.0%) respectively. Grade 3 anemia and rectal pain were observed in 4 cases (4.0%) respectively. And rectal mucositis was observed in 2 cases (2.0%). Most of the AE was observed during concurrent chemoradiotherapy. No grade 4 or higher AE was observed. After TNT, 32 patients (31.7%) achieved pCR or cCR, and 62 patients (60.4%) achieved partial response (PR). Only 2 patients (2.0%) developed distant metastasis after chemoradiotherapy, while the other patients did not show disease progression. Seven patients (6.9%) with cCR refused surgery and selected watch-and-wait, while 7 patients without cCR still refused surgery. The other 87 patients (86.1%) underwent TME successfully. The mean interval from the completion of chemoradiotherapy to surgery was (20.1±8.5) weeks. The R0 resection rate was 97.7% (85/87).The morbidity of surgical complication was 16.1% (14/87), including pelvic infection or abscess in 6 cases (6.9%), anastomotic leakage in 3 (3.4%), hemorrhage in 2 (2.3%), and gastrointestinal dysfunction in 3 (3.4%). Pathological findings revealed that 24 cases (27.6%) had TRG 0, 20 (23.0%) had TRG 1, 30 (34.5%) TRG 2, and 13 (14.9%) TRG 3. Conclusion: TNT is safe and has good short-term efficacy for locally advanced rectal cancer patients with high risk factors.


Assuntos
Quimiorradioterapia/métodos , Terapia Neoadjuvante/métodos , Neoplasias Retais/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Capecitabina/administração & dosagem , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Oxaliplatina/administração & dosagem , Protectomia , Neoplasias Retais/diagnóstico por imagem , Neoplasias Retais/patologia , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento , Conduta Expectante
8.
Zhonghua Zhong Liu Za Zhi ; 41(3): 235-240, 2019 Mar 23.
Artigo em Chinês | MEDLINE | ID: mdl-30917462

RESUMO

Objective: To investigate the clinical characteristics, therapy modality and prognosis of primary breast diffuse large B-cell lymphoma(PB-DLBCL). Methods: A total of 68 patients with PB-DLBCL treated in Tianjin Medical University Cancer Institute and Hospital were enrolled between January 1, 2004 and January 31, 2017. Clinicopathological data were retrospectively analyzed. 67 patients were female and only one male. The median age was 56 years old. 46 patients had Ann Arbor clinical stageⅠ~Ⅱ disease, and the other 22 were stage Ⅲ~Ⅳ. The patients with and without B symptom were 11 and 57, respectively. Kaplan-Meier method was used for univariate analysis to calculate the 5-year overall survival (OS) rate and 5-year progress-free survival (PFS) rate, compared using the log rank test. Cox regression analysis was used for multivariate analysis. Results: The 1, 3, 5-year OS rate were 84.0%, 78.0% and 73.0%, and 1, 3, 5-year PFS rate were 80.0%, 71.0% and 51.0%, respectively. Univariate analysis indicated that eastern cooperative oncology group (ECOG) score, Ann Arbor clinical stage, international prognostic index (IPI) score, risk stratification, B symptom, ß2-microglobulin(ß2-MG) level, size of the tumor and cycles of chemotherapy were prognostic factors for OS (all P<0.05), and Ann Arbor clinical stage, IPI score, risk stratification and B symptom were prognostic factors for PFS (all P<0.05). Multivariate analysis indicated that Ann Arbor clinical stage was independent prognostic factor for OS(P=0.029) and B symptom was independent prognostic factor for PFS(P=0.028). Conclusions: Prognosis of PB-DLBCL was relatively good. Ann Arbor clinical stage and B symptom were independent prognostic factors for OS and PFS, respectively.


Assuntos
Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Linfoma Difuso de Grandes Células B/mortalidade , Linfoma Difuso de Grandes Células B/patologia , Análise de Variância , Neoplasias da Mama/terapia , Neoplasias da Mama Masculina , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Linfoma Difuso de Grandes Células B/terapia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
10.
Environ Sci Pollut Res Int ; 22(17): 13077-82, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25925141

RESUMO

In this study, simulated fly ash containing CuO/CuCl2 was heated at 350 °C in a flow of N2 and also in a nitrogen flow containing 10 vol% H2, to evaluate the influence of hydrogen adding on dioxin formation. The total polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) output derived from the CuO sample under N2 and 10 % H2 was 7.382 and 0.708 ng/g, respectively. As for CuCl2, it was 589 and 46.1 ng/g, respectively. The results show that the hydrogen adding has a good inhibition effect on PCDD/F formation; the inhibition rate was higher than 90 % for PCDD/Fs. HCl and NH3 were detected by Gasmet in the flue gas; the probable inhibition mechanism of hydrogen reaction was proposed, based on our measurements and others' researches.


Assuntos
Cinza de Carvão/química , Dioxinas/química , Hidrogênio/química , Benzofuranos/química , Cobre/química
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