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1.
Opt Lett ; 48(22): 5879-5882, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37966742

RESUMO

In this work, the spectroscopic properties of 1.0 µm emission in Nd3+/Yb3+ co-doped phosphate glasses were systematically investigated under 808 nm excitation. Notably, broadband 1.0 µm emission with a full width at half maximum (FWHM) of 96 nm was obtained in the phosphate glass doped with 2 mol.% Nd2O3 and 1 mol.% Yb2O3. In addition, the energy transfer microscopic parameter and transfer efficiency were analyzed. What is more, multimaterial fibers with Nd3+/Yb3+ co-doped phosphate glass core and silicate cladding were successfully drawn by using the molten core method. An intense 1.0 µm amplified spontaneous emission (ASE) can be realized in a 3 cm long multimaterial fiber. More importantly, the FWHM of the ASE can reach as large as 60 nm when excited at 976 nm. These results demonstrate that the Nd3+/Yb3+ co-doped phosphate glasses and fibers are promising gain materials for amplifier and laser applications in photonics.

2.
Opt Lett ; 48(20): 5423-5426, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37831883

RESUMO

Er3+-doped glass and fiber are very attractive for near-infrared (NIR) lasers and photonic applications. In this work, the full width at half maximum (FWHM) of NIR fluorescence emission of the Er3+-doped germanate glass can be broadened from 72 to 99 nm when Al2O3 was added. In addition, the spectroscopic properties, including absorption and emission spectra, Judd-Ofelt intensity parameters, absorption and emission cross sections, gain coefficient, and fluorescence lifetime, of the Al2O3-modified germanate glass were systematically investigated. What is more, silicate-clad heavily Er3+-doped germanate core multimaterial fibers were successfully drawn by a rod-in-tube method. Notably, broadband NIR amplified spontaneous emission (ASE) with an FWHM of 120 nm was achieved in this new fiber. To the best of our knowledge, this is the largest FWHM reported for Er3+-doped germanate glass fibers. These results suggest that the as-drawn Er3+-doped germanate glass fiber with superior performances is a promising candidate for broadband optical amplification.

3.
Cell Host Microbe ; 31(7): 1154-1169.e10, 2023 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-37339625

RESUMO

Targeted protein degradation (TPD), as exemplified by proteolysis-targeting chimera (PROTAC), is an emerging drug discovery platform. PROTAC molecules, which typically contain a target protein ligand linked to an E3 ligase ligand, recruit a target protein to the E3 ligase to induce its ubiquitination and degradation. Here, we applied PROTAC approaches to develop broad-spectrum antivirals targeting key host factors for many viruses and virus-specific antivirals targeting unique viral proteins. For host-directed antivirals, we identified a small-molecule degrader, FM-74-103, that elicits selective degradation of human GSPT1, a translation termination factor. FM-74-103-mediated GSPT1 degradation inhibits both RNA and DNA viruses. Among virus-specific antivirals, we developed viral RNA oligonucleotide-based bifunctional molecules (Destroyers). As a proof of principle, RNA mimics of viral promoter sequences were used as heterobifunctional molecules to recruit and target influenza viral polymerase for degradation. This work highlights the broad utility of TPD to rationally design and develop next-generation antivirals.


Assuntos
Antivirais , Vírus , Humanos , Antivirais/farmacologia , Proteólise , RNA Viral/metabolismo , Ligantes , Vírus/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Virais/metabolismo , Proteínas de Transporte/metabolismo
4.
Stem Cells Int ; 2023: 8427767, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37274025

RESUMO

Necroptosis, a kind of programmed necrotic cell apoptosis, is the gatekeeper for the host to defend against the invasion of pathogens. It helps to regulate different biological processes regarding human cancer. Nevertheless, studies that determine the impact of death on triple-negative breast cancer (TNBC) are scarce. Therefore, this paper has comprehensively examined the expression as well as clinical significance of necroptosis in TNBC. ConsensusClusterPlus was used to establish a stable molecular classification that used the expression regarding the necroptosis-linked genes. The clinical and immune characteristics of different subclasses were evaluated. Then, the weighted gene coexpression network analysis (WGCNA) assisted in determining key modules, and we selected the genes exhibiting obvious association with necroptosis prognosis through the relationship with prognosis. The univariate Cox regression analysis together with least absolute shrinkage and selection operator (LASSO) techniques served for the construction of the necroptosis-related prognostic risk score (NPRS) model, and the pathway characteristics of NPRS model grouping were further studied. Finally, the NPRS, taking into account the clinicopathological features, used the decision tree model for enhancing the prognostic model as well as the survival prediction. First, two stable molecular subtypes with different prognosis and immune characteristics were identified using necroptosis marker genes. Then, the key modules were identified, and 10 genes significantly related to the prognosis of necroptosis were selected. Then, the clinical prognostic model of NPRS was developed considering the prognosis-linked necroptosis genes. Finally, the NPRS model, taking into account the clinicopathological features, adopted the decision tree model for enhancing the prognostic model as well as the survival prediction. Herein, two new molecular subgroups considering necroptosis-linked genes are proposed, and an NPRS model composed of 10 genes is developed, which maybe assist in the personalized treatment and clinical treatment guidance of TNBC patients.

5.
Front Surg ; 10: 1043329, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36936657

RESUMO

Background: The Clavien-Dindo classification (CDC) has been widely accepted and applied in clinical practice. We investigated its effectiveness in prediction of major complications (LPPC) after laparoscopic pancreaticoduodenectomy (LPD) and associated risk factors. Methods: A retrospective analysis was conducted covering clinical data of 793 patients undergoing LPD from April 2015 to November 2021. CDC was utilized to grade postoperative complications and analyze the differences. Risk factors of LPPC were identified according to univariate and multivariate analyses. Resluts: For the 793 patients undergoing laparoscopic pancreaticoduodenectomy in the northeast of China, LPPC was reported in 260 (32.8%) patients, pancreatic fistula in 169 (21.3%), biliary fistula in 44 (5.5%), delayed gastric emptying in 17(2.1%), post pancreatectomy hemorrhage in 55 (6.9%), intestinal fistula in 7 (0.8%), abdominal infections in 59 (7.4%) and pulmonary complication in 28 (3.5%). All complications were classified into five levels with the C-D classification (Grade I-V), with 83 (31.9%) patients as grade I, 91 (35.0%) as grade II, 38 (14.6%) as grade IIIa, 24 (9.2%) as grade IIIb, 9 (3.5%) as grade IV and 15 (5.8%) as grade V. 86 (10.8%) patients experienced major complications (grade III-V).The results of univariate and multivariate analysis revealed the independent risk factors for laparoscopic pancreaticoduodenectomy complications to be preoperative total bilirubin (P = 0.029, OR = 1.523), soft pancreas texture (P < 0.001, OR = 1.399), male (P = 0.038, OR = 1.396) and intraoperative transfusion (P = 0.033, OR = 1.517). Preoperative total bilirubin (P = 0.036, OR = 1.906) and intraoperative transfusions (P = 0.004, OR = 2.123) were independently associated with major postoperative complications. The influence of different bilirubin levels on C-D grade of complications was statistically significant (P = 0.036, OR = 1.906). Conclusions: The Clavien-Dindo classification (CDC) may serve as a valid tool to predict major postoperative complications and contribute to perioperative management and comparison of surgical techniques in different medical centers.

6.
Opt Lett ; 48(3): 534-537, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36723524

RESUMO

Rare-earth (RE) ions doped laser glass has attracted the interest of many researchers because of its numerous potential applications in planar waveguides and fiber lasers. In this work, the 2-µm and upconversion luminescence properties of Ho3+ are simultaneously enhanced through the design of components used to regulate the network structure of the germanate glass. Furthermore, the thermal, structural, and spectroscopic properties of the Ho3+/Yb3+ co-doped germanate laser glass are systematically investigated. It is noted that the calculated gain coefficient of the Nb2O5 modified germanate laser glass can reach as high as 3.05 cm-1 at 2047 nm. These results suggest that the prepared germanate laser glass with superior performances is a promising candidate for 2-µm mid-infrared laser materials applications.

7.
Front Oncol ; 13: 1053375, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36761960

RESUMO

Background: Pancreatic cancer is one of the most malignant cancers worldwide, and it mostly occurs in the head of the pancreas. Existing laparoscopic pancreaticoduodenectomy (LPD) surgical techniques have has undergone a learning curve, a wide variety of approaches for the treatment of pancreatic cancer have been proposed, and the operation has matured. At present, pancreatic head cancer has been gradually changing from "surgeons' evaluation of anatomical resection" to "biologically inappropriate resection". In this study, the risk of lymph node metastasis in pancreatic head cancer was predicted using common preoperative clinical indicators. Methods: The preoperative clinical data of 191 patients with pancreatic head cancer who received LPD in the First Affiliated Hospital of Jilin University from May 2016 to December 2021 were obtained. A univariate regression analysis study was conducted, and the indicators with a significance level of P<0.05 were included in the univariate logistic regression analysis into multivariate. Lastly, a nomogram was built based on age, tumor size, leucocyte,albumin(ALB), and lymphocytes/monocytes(LMR). The model with the highest resolution was selected by obtaining the area under a curve. The clinical net benefit of the prediction model was examined using decision curve analyses.Risk stratification was performed by combining preoperative CT scan with existing models. Results: Multivariate logistic regression analysis found age, tumor size, WBC, ALB, and LMR as five independent factors. A nomogram model was constructed based on the above indicators. The model was calibrated by validating the calibration curve within 1000 bootstrap resamples. The ROC curve achieved an AUC of 0.745(confidence interval of 95%: 0.673-0.816), thus indicating that the model had excellent discriminative skills. DCA suggested that the predictive model achieved a high net benefit in the nearly entire threshold probability range. Conclusions: This study has been the first to investigate a nomogram for preoperative prediction of lymphatic metastasis in pancreatic head cancer. The result suggests that age, ALB, tumor size, WBC, and LMR are independent risk factors for lymph node metastasis in pancreatic head cancer. This study may provide a novel perspective for the selection of appropriate continuous treatment regimens, the increase of the survival rate of patients with pancreatic head cancer, and the selection of appropriate neoadjuvant therapy patients.

8.
Opt Express ; 30(18): 32693-32703, 2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36242325

RESUMO

High-gain Tm3+/Ho3+ co-doped optical fibers are urgently desired for high-repetition-rate mode-locked fiber lasers at >2 µm. Here, Tm3+/Ho3+ co-doped germanate glass with low hydroxyl (OH-) content was prepared by the conventional melt-quenching method combined with the reaction atmosphere procedure (RAP) dehydration technique. The doping concentrations of Tm2O3 and Ho2O3 are 2.5 mol.% (7.1 wt.%) and 0.25 mol.% (0.7 wt.%), respectively. Thanks to the high Tm3+ doping (7.1 wt.%) and low energy transfer efficiency (19.8%) between Tm3+ and Ho3+ ions, it enables achieving broadband and high-gain performance in the 2 µm region. Then a silicate-clad Tm3+/Ho3+ co-doped germanate core multimaterial fiber was successfully drawn by using the rod-in-tube method, which has a broadband amplified spontaneous emission (ASE) with a full width at half-maximum (FWHM) of 247.8 nm at 2 µm. What is more, this new fiber has a high gain per unit length of 4.52 dB/cm at 1.95 µm. Finally, an all-fiber-integrated passively mode-locked fiber laser was built by using this broadband high-gain fiber. The mode-locked pulses operate at 2068.05 nm, and the fundamental repetition rate is up to 4.329 GHz. To the best of our knowledge, this is the highest fundamental repetition rate for the all-fiber passively mode-locked fiber laser above 2 µm. These results suggest that the as-drawn multimaterial fibers with broadband high-gain characteristics are promising for high-repetition-rate ultrafast fiber lasers.

9.
Math Biosci Eng ; 19(1): 191-208, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34902987

RESUMO

Pancreatic cancer (PC) is a highly fatal disease correlated with an inferior prognosis. The tumor protein p53 (TP53) is one of the frequent mutant genes in PC and has been implicated in prognosis. We collected somatic mutation data, RNA sequencing data, and clinical information of PC samples in the Cancer Genome Atlas (TCGA) database. TP53 mutation was an independent prognostic predictor of PC patients. According to TP53 status, Gene set enrichment analysis (GSEA) suggested that TP53 mutations were related to the immunophenotype of pancreatic cancer. We identified 102 differentially expressed immune genes (DEIGs) based on TP53 mutation status and developed a TP53-associated immune prognostic model (TIPM), including Epiregulin (EREG) and Prolactin receptor (PRLR). TIPM identified the high-risk group with poor outcomes and more significant response potential to cisplatin, gemcitabine, and paclitaxel therapies. And we verified the TIPM in the International Cancer Genome Consortium (ICGC) cohort (PACA-AU) and Gene Expression Omnibus (GEO) cohort (GSE78229 and GSE28735). Finally, we developed a nomogram that reliably predicts overall survival in PC patients on the bias of TIPM and other clinicopathological factors. Our study indicates that the TIPM derived from TP53 mutation patterns might be an underlying prognostic therapeutic target. But more comprehensive researches with a large sample size is necessary to confirm the potential.


Assuntos
Neoplasias Pancreáticas , Proteína Supressora de Tumor p53 , Humanos , Mutação , Nomogramas , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Prognóstico , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
10.
Opt Express ; 29(14): 22667-22678, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34266025

RESUMO

In museum lighting, traditional Chinese paintings are the artworks with the highest light sensitivity. They are vulnerable to the color damage to pigments and the mechanical damage to substrates after the irradiation from light sources. As the basis of effective preventive protection, the research on the two lighting quantity indexes of illuminance and annual exposure (illuminance × time) is currently missing. In this study, the halogen lamp was used as the experimental light source to conduct a 1440 h irradiation experiment on the samples of paper and silk substrates under 4 illuminance levels, respectively, and the test of infrared spectrum was carried out on the samples every 240 h. The oxidation index of paper and crystallinity degree of silk were calculated then. Three-dimensional visual curved surface plots of mechanical damage to samples with the change of illuminance and time were established and then fitted into damage evaluation equations, which revealed and described mathematically the mechanical damage law of samples. Through the equations, the recommended values of illuminance and annual exposure for samples could be calculated. Combining the previous researches on pigments, the lighting quantity indexes of traditional Chinese paintings with different combinations of substrates and pigments were proposed.

11.
Sci Rep ; 11(1): 10951, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34040105

RESUMO

Dyed artworks are highly sensitive to light and are easily affected by museum lighting, resulting in irreversible permanent color damage such as fading and discoloration. Exposure, light source spectrum and material properties are the three indicators causing damage to artworks. Therefore, it is the basis for effective lighting protection to reveal the quantitative influence of exposure and light source spectrum composition on the damage degree of different pigments and establish a mathematical model that can accurately express the above rules. At present, the color damage calculation model of dyed artworks under three parameters' coupling action is missing. This research established a visual three-dimensional change surface of the color difference values of 23 pigments varying with the spectral wavelength and exposure through experimental methods. The relative responsivity function ΔEn = fn(λ, Q), where n = 1 ~ 23, was obtained for 23 pigments under the coupling effects of exposure and light source spectra. Furthermore, a mathematical model [Formula: see text] calculating the color damage of pigments in the range of visible light was proposed. The proposed model was verified by the experimental method, which realizes the mathematical expression of the damage law of museum lighting on dyed artworks.

12.
Ther Adv Med Oncol ; 13: 17588359211009003, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33959195

RESUMO

BACKGROUND: Although dual blockade HER2-based neoadjuvant chemotherapy is associated with excellent outcomes for human epidermal growth factor receptor 2 (HER2)-positive breast cancer, pertuzumab is not available to all patients due to cost. The optimal neoadjuvant chemotherapy for HER2-positive breast cancer in the presence of a single HER2 blockade is unknown. This study aimed to compare the efficacy and safety of epirubicin/cyclophosphamide followed by docetaxel/trastuzumab (EC-TH) with docetaxel/carboplatin/trastuzumab (TCH) neoadjuvant setting for HER2-positive breast cancer under the single HER2 blockade. METHODS: Patients with stage II-IIIC HER2-positive breast cancer were randomly assigned to either eight cycles of EC-TH every 3 weeks during all chemotherapy cycles, or six cycles of TCH every 3 weeks. The primary endpoint was pathological complete response (pCR) (defined as the absence of invasive tumor cells in breast and axilla, ypT0/is ypN0). RESULTS: From May 2017 to November 2019, 140 patients were randomly assigned, and 135 patients were ultimately found evaluable for the primary endpoint. The pCR was recorded in 25 of 67 patients [37.3%; 95% confidence interval (CI), 25.8-50.0] in the EC-TH group and in 38 of 68 patients (55.9%, 95% CI, 43.3-67.9) in the TCH group (p = 0.032). The most common adverse events (AEs) were neutropenia in 24 of 67 (35.8%) patients in the EC-TH group versus 27 of 68 (39.7%) in the TCH group (p = 0.642), anemia in 33 of 67 (49.3%) patients in the EC-TH group versus 34 of 68 (50.0%) in the TCH group (p = 0.931), and thrombocytopenia in five of 67 (7.5%) patients in the EC-TH group versus 17 of 68 (25.0%) in the TCH group (p = 0.006). CONCLUSION: For patients receiving the single HER2 blockade trastuzumab for HER2-positive breast cancer, TCH regimen might be a preferred neoadjuvant therapy. TRIAL REGISTRATION: This trial was registered with ClinicalTrials.gov identifier: NCT03140553) on 2 May 2017.

13.
Appl Opt ; 59(15): 4599-4605, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32543568

RESUMO

Because commonly used organic pigments are highly responsive to visible light, high-light-sensitivity art is vulnerable to irreversible illumination-induced damage caused by radiation from light sources. With application of the four primary white light-emitting diodes (fp-WLEDs) in museums, it is urgent to evaluate the illumination-induced damage to high-light-sensitivity art caused by the fp-WLEDs. Four narrowband LEDs with different peak wavelengths of 450, 510, 583, and 650 nm that constitute the spectra of the fp-WLEDs were used to irradiate three commonly used organic pigments: safflower, gamboge, and indigo. Based on the fundamental reason for the illumination-induced damage, that is, photochemical reactions, Raman spectroscopy was introduced into the study. The Raman spectra of pigments were measured before and after illumination. The characteristic Raman peaks corresponding to the functional groups that determine color and structure of pigments were selected, and the variations in their peak intensities were calculated. The illumination-induced damage coefficients of four narrowband LEDs on three organic pigments were obtained, providing a data basis for illumination-induced damage evaluation equation proposed in this study, which was expected to further realize museum admission evaluation of the new fp-WLEDs.

14.
Infect Genet Evol ; 82: 104293, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32247035

RESUMO

Salmonella is an important pathogen for public health due to food poisoning and acute infectious intestinal disease by zoonotic trait. We isolated Salmonella enterica QH which represents the normal growth condition in Luria-Bertani culture and displays a wide range of susceptibility for multiple antibiotics. To further investigate genetic and pathogenic traits of S. enterica QH, the sequencing genome of S. enterica QH and oral Salmonella infection in mice were performed in this study. Compared with other Salmonella strains, several large sequences containing prophages and genomic islands were inserted into S. enterica QH genome. Furthermore, nucleotide and synonymous codon usage patterns display mutation pressure and natural selection serving as drivers for the evolutionary trend of S. enterica QH at gene level. The unique codon usage pattern of S. enterica QH probably contributes to adaptation to environmental/host niches and to pathogenicity. In an early oral S. enterica QH infection, the levels of CD4+ and CD8+ lymphocytes significantly reduce in peripheral blood of mice, but the increasing transcription levels of some cytokines (IFN-ß1, IFN-γ and CXCL10) might have pleiotypic immune effects against S. enterica QH infection. Of note, IL10 displays significant enhancement at levels of transcription and translation, suggesting that immunosuppressive effects mediated by IL10 may function as an early oral S. enterica QH infection. The systemic investigations, including genomic and genetic characterizations and biological traits of S. enterica QH in vivo and in vitro may reflect the basic lifestyle of S. enterica QH, requiring intestine colonization, undergoing environmental stresses and performing dissemination.


Assuntos
Salmonelose Animal/microbiologia , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/genética , Salmonella enterica/patogenicidade , Animais , Antibacterianos/farmacologia , Bovinos/microbiologia , China , Uso do Códon , Citocinas/genética , Citocinas/metabolismo , Farmacorresistência Bacteriana/genética , Feminino , Genoma Bacteriano , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Leite/microbiologia , Salmonelose Animal/sangue , Salmonelose Animal/imunologia
15.
Biotechnol Biofuels ; 12: 57, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30923565

RESUMO

BACKGROUND: The presence of lignin normally affects enzymatic saccharification of lignocellulose detrimentally. However, positive effects of lignin on enzymatic hydrolysis have been recently reported. Enzyme-lignin interactions could be the key to reveal the underlying mechanism of their discrepant behaviors. In this study, to elucidate the positive effects of extractable lignin (EL) on enzymatic hydrolysis of ethanol organosolv-pretreated wood sawdust, two lignin fractions, EL and milled wood lignin (MWL), were isolated sequentially from pretreated substrates. Quartz crystal microbalance with dissipation (QCM-D) was then used to investigate the lignin aggregation effects on enzyme adsorption. RESULTS: We found that both EL and MWL had a narrow molecular weight distribution. However, MWL had an obviously higher molecular weight than EL. This indicated that EL and MWL likely represent two distinct lignin fractions from ethanol organosolv-pretreated substrates. HSQC NMR analysis revealed that less ß-O-4, ß-ß, and ß-5 linkages and a higher S/G ratio was present in EL, as compared to MWL. QCM-D analysis showed that the enzyme adsorption on lignin was highly relevant to these lignin structural characteristics. An obviously lower maximum enzyme adsorption capacity was observed on EL films (152.63-168.09 ng/cm2) compared to MWL films (196.71-224.73 ng/cm2). Furthermore, enzyme desorption on lignin films was determined. A significantly lower irreversible enzyme adsorption was observed on EL (75.40 ng/cm2) compared to MWL (137.35 ng/cm2). More importantly, two reconstructed lignin films were designed to investigate lignin assembly on enzyme adsorption. The results indicated that the presence of EL reduced irreversible enzyme adsorption on the reconstructed lignin films by 39.2-45.0%. CONCLUSIONS: Lignin structure determined the interaction between enzyme and lignins. A positive correlation was observed between molecular weight, the content of ß-5 linkages, and enzyme adsorption on lignin. EL, which was more depolymerized and less condensed, had the lower enzyme adsorption of the two preparations tested. Additionally, the presence of EL reduced enzyme adsorption on reconstructed lignin films, perhaps through a mechanism involving the blocking of non-productive enzyme binding sites on the MWL. This could be the mechanism for the positive effects of EL on enzymatic hydrolysis.

16.
Angew Chem Int Ed Engl ; 58(13): 4345-4349, 2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-30791181

RESUMO

A selectivity switch in a RhII /carbene-triggered cyclopentannulation with catalytic InCl3 is reported for the first time, affording both diastereomers of the fused spiroindolines and an unusual bridged tetracyclic indoline in high yields with excellent selectivities. Mechanistic studies indicate an intramolecular annulation of the indole with an in situ formed aminocyclopropane. The stepwise thermal conversions from the kinetic spiroindoline to the metastable bridged indoline, and then to the thermodynamic spiroindoline, involving a ring-opening rearrangement of a cyclopentane, is crucial for selectivity control.

17.
ACS Macro Lett ; 8(3): 299-303, 2019 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-35650832

RESUMO

Synthesis of a variety of optically transparent polyolefin elastomers consisting of hard segment of polynorbornene and several kinds of soft segments such as atactic polypropylene, poly(ethylene-co-propylene), and poly(ethylene-co-1-hexene) was achieved. The block copolymers exhibited excellent toughness and thermal property with efficient elastic recovery. Most importantly, the introduction of hydroxyl group into polynorbornene segment not only modulated surface property of block copolymers, but also improved their mechanical properties.

18.
Bioresour Technol ; 269: 18-24, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30145521

RESUMO

Effects of the addition of 2-naphthol and 2-naphthol-7-sulfonate on the dilute acid pretreatment of mixed wood sawdust were investigated, respectively. Compared to 2-naphthol, 2-naphtnol-7-sulfonate was more effective to enhance delignification and facilitate the enzymatic hydrolysis. The 72 h hydrolysis yield was improved by 47.8% for 2-naphthol-7-sulfone, while only 9.1% was observed for 2-naphthol. The surface charges, enzyme adsorption, and cellulose accessibility of dilute acid pretreated substrates with or without naphthol derivatives were examined. The improved enzymatic hydrolysis by adding 2-naphthol-7-sulfonate was ascribed to the higher negative surface charges, the lower enzyme non-productive binding, and the higher cellulose accessibility of pretreated substrates. Additionally, the HSQC NMR and 31P NMR analysis were carried out on both decomposed lignins and residual bulk lignins. It indicated that the addition of the naphthol derivatives during pretreatment could suppress the lignin repolymerization, which further mitigated the inhibition of residual lignins on enzymatic hydrolysis.


Assuntos
Celulose/metabolismo , Lignina , Celulase , Hidrólise , Naftóis , Madeira
19.
Org Lett ; 20(13): 3858-3861, 2018 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-29888607

RESUMO

Nickel-catalyzed asymmetric annulation of oxygenated phenols and previously challenging 3-aminophenols with ß,γ-unsaturated α-ketoesters is described, leading to rapid access to a variety of oxygenated and 7-aminated chromans in excellent yields with excellent diastereoselectivities and enantioselectivities under mild conditions. This method was readily scaled-up to gram scale and applied for a concise synthesis of two potential anticancer agents 7-aminated 4-arylchromans.

20.
J Cancer ; 9(10): 1782-1790, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29805704

RESUMO

The increasing frequency of early breast cancer cases has driven an increasing number of patients to choose immediate reconstruction with an autologous flap. Omentum-flap-based breast reconstruction is a unique strategy that is highly suitable for repairing moderate tissue defects. However, all available evidence comes from individual reports with small numbers of cases, and the overall effectiveness and safety of the procedure have yet to be reported. Here, we reported 7 cases of laparoscopically harvested omental free flap breast reconstruction and performed a systematic review to assess the applicability and safety of this approach. The data were gathered from MEDLINE, Ovid, Google Scholar and the China Knowledge Resource Integrated Database. In total, we combined 15 articles (410 cases) for analysis. The data revealed that almost all patients (87.6%) were reported to have undergone laparoscopy instead of laparotomy; pedicle flaps were used in 90.9% of the cases, while only 5 (37 cases) used free flaps for reconstruction; and 96.6% (396/410) of all reconstruction procedures were immediate. Almost all of these cases had a small tumour burden (T0/Tis/T1 59.8%; T2 36.8%), and the distribution of tumour location was similar among the four quadrants. The cosmetic outcomes were desirable in most cases (83.9%). There were 41 complications identified in the dataset: partial graft necrosis accounted for the largest percentage (41.5%) of all events, followed by skin necrosis (19.5%), haematoma (12.2%) and wound infection (9.8%). During the follow-up period, which had a short median duration, 2 cases of tumour recurrence were reported. Overall, our systematic review found that omentum-flap-based breast reconstruction could achieve a satisfactory aesthetic outcome, especially for small breasts and tissue replacement after breast-conserving surgery, and the safety of the procedure was also acceptable.

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