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1.
Talanta ; 221: 121399, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33076054

RESUMO

Herein, we present a facile strategy for dopamine (DA) sensing by a water-stable MOF of {[Tb(Cmdcp)(H2O)3]2(NO3)2·5H2O}n (1, H3CmdcpBr = N-carboxymethyl-(3,5-dicarboxyl)pyridinium bromide). Without any post-modification, MOF 1 functions as an effective fluorescent sensor for the label-free detection of DA with the detection limit of 0.41 µM (S/N = 3). Under the optimum condition of 80 °C, pH 9 for 80 min in Tris-HCl with natural ambient oxygen, DA polymerizes to give polydopamine (pDA), which adheres to the surface of MOF 1 and quenched its green luminescence thoroughly. The sensing process is visible to naked eyes under 365 nm UV light irradiation due to the partial overlap of its excitation spectrum with the absorption spectrum of pDA. The sensing process is not interfered by coexisting of bio-related organic substances, such as glucose (Glu), 5-hydroxytryptamine (5-HT), homocysteine (Hcy), ascorbic acid (AA), uric acid (UA), cysteine (Cys), glutathione (GSH), as well as the presence of metal ions, including Zn2+, Ca2+, Mg2+, Ni2+ and Co2+. The sensing process is also adaptable in biological fluids of serum and urine with satisfactory recoveries ranging from 96.14% to 104.32%.

2.
Clin Interv Aging ; 15: 2083-2094, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33192055

RESUMO

Purpose: Our objectives were to assess the abnormalities of subcortical nuclei by combining volume and shape analyses and potential association with cognitive impairment. Patients and Methods: Twenty-nine patients with severe ACS of the unilateral internal carotid artery and 31 controls were enrolled between January 2017 to August 2018. All participants underwent a comprehensive neuropsychological evaluation, blood lipid biochemical measurements, and structural magnetic resonance imaging (MRI) to measure subcortical volumes and sub-regional shape deformations. Basic statistics, correction for multiple comparisons. Seventeen ACS patients underwent carotid endarterectomy (CEA) within one week after baseline measurements, cognitive assessments and MRI scans were repeated 6 months after CEA. Results: The ACS patients had higher apolipoprotein B/apolipoprotein A1 (ApoB/ApoA1) ratio and worse performance in all cognitive domains than controls. Moreover, the ACS patients showed more profound thalamic atrophy assessed by shape and volume analysis, especially in the medial dorsal thalamus. No significant differences were found in other subcortical nuclei after multiple comparisons correction. At baseline, thalamic atrophy correlated with cognitive impairment and ApoB/ApoA1 ratio. Furthermore, mediation analysis at baseline showed that the association of carotid intima-media thickness with executive functioning was mediated by thalamic volume. After CEA, cognitive improvement and increase in the bilateral medial dorsal thalamic volume were observed. Conclusion: Our study identified the distinct atrophy of subcortical nuclei and their association with cognition in patients with ACS. Assessments of the thalamus by volumetric and shape analysis may provide an early marker for cerebral ischemia and reperfusion after CEA.

3.
Stoch Environ Res Risk Assess ; : 1-18, 2020 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-33223954

RESUMO

Novel coronavirus (COVID-19) is a new strain of coronavirus first identified in Wuhan, China. As the virus spread worldwide causing a global pandemic, China reduced transmission at considerable social and economic cost. Post-lockdown, resuming work safely, that is, while avoiding a second epidemic outbreak, is a major challenge. Exacerbating this challenge, Beijing hosts many residents and workers with origins elsewhere, making it a relatively high-risk region in which to resume work. Nevertheless, the step-by-step approach taken by Beijing appears to have been effective so far. To learn from the epidemic progression and return-to-work measures undertaken in Beijing, and to inform efforts to avoid a second outbreak of COVID-19, we simulated the epidemiological progression of COVID-19 in Beijing under the real scenario of multiple stages of resuming work. A new epidemic transmission model was developed from a modified SEIR model for SARS, tailored to the situation of Beijing and fitted using multi-source data. Because of strong spatial heterogeneity amongst the population, socio-economic factors and medical capacity of Beijing, the risk assessment was undertaken spatiotemporally with respect to each district of Beijing. The epidemic simulation confirmed that the policy of resuming work step-by step, as implemented in Beijing, was sufficient to avoid a recurrence of the epidemic. Moreover, because of the structure of the model, the simulation provided insights into the specific factors at play at different stages of resuming work, allowing district-specific recommendations to be made with respect to monitoring at different stages of resuming work . As such, this research provides important lessons for other cities and regions dealing with outbreaks of COVID-19 and implementing return-to-work policies.

4.
J Int Med Res ; 48(10): 300060520966884, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33135534

RESUMO

OBJECTIVE: To assess the biomechanical properties that influence wrist fracture, so as to provide the theoretical basis for simulation experiments to aid the optimal design of wrist protectors. METHODS: Six cadaveric wrists were included as experimental specimens. Wrist specimens wearing wrist protectors formed the experimental group and unprotected wrist specimens formed the control group. The wrist specimens were axially loaded under physiological loads and the stress magnitude and distribution of the experimental and control groups were obtained. A three-dimensional wrist finite element model of a healthy volunteer was developed to verify the rationality and effectiveness of the cadaveric wrist models. RESULTS: Under normal physiological loads, the stress on the radioulnar palmar unit was high and manifested in the form of pressure, while the stress on the radioulnar dorsal unit was lower and manifested in the form of tension. The stresses on the radial distal palmar, ulnar distal palmar, radial distal dorsal, ulnar distal dorsal, radial proximal palmar and ulnar proximal palmar units in the experimental group were less than those in the control group. CONCLUSION: Under physiological loads, wearing a wrist protector can reduce the stress on the radioulnar distal palmar, radioulnar proximal palmar and radioulnar distal dorsal units, while having no obvious effect on the radioulnar proximal dorsal units.

5.
Sci Rep ; 10(1): 18880, 2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33144606

RESUMO

Currently, controversies regarding the optimal time-point of anti-vascular endothelial growth factor (VEGF) pretreatment before pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR) still exist. To clarify this, we conducted a network meta-analysis, 26 randomized controlled trials including 1806 PDR patients were included. Compared with the sham group, performing anti-VEGF injection at preoperative (Pre-Op) 6 to 14 days could significantly improve post-operative best-corrected visual acuity (BCVA) and decrease the incidence of recurrent vitreous hemorrhage (VH). Meanwhile, it could significantly reduce the duration of surgery. Performing anti-VEGF injection at Pre-Op more than 14 days, 6 to 14 days or 1 to 5 days could significantly reduce the incidence of intra-operative bleeding, while no significant benefit existed at the end of PPV (P > 0.05). No significant difference existed between all those strategies and sham group in reducing the rate of silicone oil tamponade. Based on currently available evidence, performing the anti-VEGF pretreatment at pre-operative 6 to 14 days showed best efficacy in improving post-operative BCVA, reducing the duration of surgery and incidence of recurrent VH, it also achieves satisfactory effect in reducing the incidence of intra-operative bleeding.

6.
Orphanet J Rare Dis ; 15(1): 312, 2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-33153463

RESUMO

BACKGROUND: Mandible osteomyelitis can occur in synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome, a rare chronic inflammatory disease; however, few studies have explored its characteristics and management. METHODS: We reviewed the medical records of consecutive SAPHO patients with mandible involvement diagnosed in Peking Union Medical College Hospital from September 2014 to July 2019. Demographic, clinical, laboratory, and imaging data were collected at baseline. Prescription data and follow-up magnetic resonance imaging (MRI) and cone beam computed tomography (CBCT) images were collected from the hospital information system. An electronic questionnaire was distributed to all patients to obtain their latest symptoms. RESULTS: A total of 26 SAPHO patients with mandibular involvement were involved, all of whom responded to the questionnaire (38.5% male; median age, 28 years; median follow-up duration, 2.1 years). Ten patients (38.5%) had undergone an oral procedure 1 month before the onset of mandibular symptoms. All 14 of the patients who underwent a surgical intervention relapsed within a median duration of 2 months (range 0.25-4.0 months), and 24 patients (92.3%) achieved improvement with conservative treatment. Following bisphosphonate treatment, remission of bone marrow oedema and osteolysis was observed on MRI and CBCT, and 5 patients receiving bisphosphonates with follow-up CBCT after remission did not relapse in 5.4 months (mean 6.0, range 3.2-9.9 months). CONCLUSION: Mandibular involvement of SAPHO syndrome predominantly occurs in young women. Dental procedures are a possible risk factor. Conservative treatment, especially intravenous bisphosphonates, can lead to oral improvement.

7.
Soft Robot ; 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33180656

RESUMO

Soft robots show excellent body compliance, adaptability, and mobility when coping with unstructured environments and human-robot interactions. However, the moving speed for soft locomotion robots is far from that of their rigid partners. Rolling locomotion can provide a promising solution for developing high-speed robots. Based on different rolling mechanisms, three rolling soft robot (RSR) prototypes with advantages of simplicity, lightweight, fast rolling speed, good compliance, and shock resistance are fabricated by using dielectric elastomer actuators. The experimental results demonstrate that the impulse-based and gravity-based RSRs can move both stably and continuously on the ground with a maximum speed higher than 1 blps (body length per second). The ballistic RSR exhibits a high rolling speed of ∼4.59 blps. And during its accelerating rolling process, the instantaneous rolling speed of the robot prototype reaches about 0.65 m/s (13.21 blps), which is much faster than most of the previously reported locomotion robots driven by soft responsive materials. The structure design and implementation methods based on different rolling mechanisms presented can provide guidance and inspiration for creating new, fast-moving, and hybrid mobility soft robots.

8.
Artigo em Inglês | MEDLINE | ID: mdl-33180984

RESUMO

Polymeric materials possessing both high refractive indices and high Abbe numbers are much in demand for the development of advanced optical devices. However, the synthesis of such functional materials is a challenge because of the trade-off between these two properties. Herein, a synthetic strategy is presented for enhancing the optical properties of CO 2 -based polycarbonates by modifying the polymer's topological structure. Terpolymers with thiocarbonate and carbonate units randomly distributed in the polymers' main chain were synthesized via the terpolymerization of cyclohexene oxide with a mixture of CO 2 and COS in the presence of metal catalysts, most notably a dinuclear aluminum complex. DFT calculations were employed to explain why different structural sequence were obtained with distinct bimetallic catalysts. Varying the CO 2 pressure made it possible to obtain terpolymers with tunable carbonate linkages in the polymer chain. More importantly, optical property studies revealed that terpolymers with comparable thiocarbonate and carbonate units exhibited a refractive index of 1.501 with an enhanced Abbe number as high as 48.6, much higher than the corresponding polycarbonates or polythiocarbonates. Additionally, all terpolymers containing varying thiocarbonate content displayed good thermal properties with T g > 109 °C and T d > 260 °C, suggesting little loss in the thermal stability compared to the polycarbonate. Hence, modification of the topological structure of the polycarbonate is an efficient method of obtaining polymeric materials with enhanced optical properties without compromising thermal performance.

9.
Ann Palliat Med ; 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33183050

RESUMO

BACKGROUND: Lichen simplex chronicus (LSC) is an acquired chronic dermatosis that is often accompanied by severe paroxysmal pruritus, and its pathogenesis to date is still unclear. Transient receptor potential channel A1 (TRPA1) is a non-selective cation channel. TRPA1 is widely expressed in skin, sensory neurons, and various other tissues, along with various biological functions and activation mechanisms. This study aimed to explore the changes in TRPA1 expression in human LSC and provide evidence for further research on the role of TRPA1 in chronic pruritus. METHODS: A total of 21 skin lesion specimens from LSC patients with skin pruritus lasting more than 6 weeks, and 28 normal skin tissue specimens through the skin biopsy from June 2018 to February 2019 were collected. The expression of TRPA1 in these skin tissues was evaluated through western blotting, quantitative reverse transcription PCR (qRT-PCR), and immunohistochemical analysis. The changes of inflammatory mediators, including interleukin (IL)-6, IL-13, endothelin-1 (ET-1), and thymic stromal lymphopoietin (TSLP), as well as substance P, are also analyzed by qRT-PCR. TRPA1 was detected using immunohistochemistry for all skin layers, the basal layer, and around the blood vessels of the dermis. RESULTS: The expression of TRPA1 in LSC specimens was significantly decreased as compared with that in the normal specimens (P<0.05). Also, TRPA1 protein levels were consistently decreased in LSC specimens (P<0.05). Simultaneously, the mRNA expressions of TRPA1, IL-6, IL-13, ET-1, TSLP, and substance P presented with no significant differences between LSC and normal specimens. CONCLUSIONS: TRPA1 expression is proved downregulated in skin lesions of LSC patients with skin pruritus, indicating that TRPA1 serves as a crucial role in the pathogenesis of human LSC.

10.
Am J Cardiol ; 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33159905

RESUMO

We aimed to explore the utility of multiple biomarkers with GRACE risk stratification for non-ST-elevation myocardial infarction (NSTEMI). A total of 1,357 patients diagnosed with NSTEMI were enrolled in this study at multiple medical centers in Tianjin, China. The outcomes were 1-year all-cause death and major adverse cardiac events (MACE: all-cause death, hospital admission for unstable angina, hospital admission for heart failure, nonfatal recurrent myocardial infarction, and stroke). C-index, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were calculated to verify that the biomarkers improve the predictive accuracy of the GRACE score. A total of 57 participants died, while 211 participants experienced 231 MACEs during follow-up (mean: 339 days). For all-cause death, the combination of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and D-dimer improved the predictive accuracy of GRACE the most, with C-index, IDI, and NRI values of 0.88, 0.085, and 1.223, respectively. For MACE, trigeminal combination of NT-proBNP, fibrinogen, and D-dimer resulted in C-index, IDI, and NRI values of 0.80, 0.079, and 0.647, respectively. As a result, NT-proBNP, D-dimer, fibrinogen, and GRACE comprise a new scoring system for assessing 1-year clinical events. Kaplan-Meier analysis revealed a significant increase in 1-year mortality (score ≥3.85 vs <3.85, p < 0.0001) and 1-year MACE (score ≥1.72 vs <1.72, p < 0.0001) between different score groups. In conclusion, the combination of NT-proBNP and D-dimer added prognostic value to GRACE for all-cause death. Combining NT-proBNP, fibrinogen, and D-dimer increased the prognostic value of GRACE for MACE. This newly developed scoring system is strongly correlated with all-cause mortality and MACE, and can be easily utilized in clinical practice.

11.
Mol Med Rep ; 22(6): 5399-5411, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33173979

RESUMO

Reperfusion is a critical therapeutic intervention used following acute ischemic stroke; however, it may cause cerebral ischemia/reperfusion injury (CIRI) and aggravate brain damage. Piceatannol (Pic), a hydroxylated analog of resveratrol, has been reported to exhibit anti­inflammatory effects. However, the detailed molecular mechanisms and its effects on CIRI have not been sufficiently assessed, and, to the best of our knowledge, current methods of prevention of CIRI are limited. The aim of the present study was to investigate the effects of Pic on improving neurological function in a mouse model of CIRI. For the animal experiments, 8­week­old C57BL/6 mice were raised and randomly grouped, and an in vivo model of CIRI was established. Mice were administered a low (10 mg/kg/day) or high­dose (20 mg/kg/d) of Pic 1 h after CIRI orally and once daily for the next 6 days. Neurological dysfunction was assessed using a modified neurological severity score and a rotarod test 1 week after CIRI establishment, and the cognitive status of the mice was assessed using a Morris water maze. Hematoxylin and eosin staining was used to evaluate the histopathological changes. The expression levels of sirtuin 1 (Sirt1), FoxO1, cleaved caspase­3 (CC­3), Bax and Bcl­2 were measured using western blotting. Intracellular reactive oxygen species (ROS) generation, antioxidant enzymes [superoxide dismutase, glutathione (GSH) peroxidase and catalase] and non­enzymatic antioxidants (GSH) were also detected using spectrophotometry. After inhibition of the Sirt1/FoxO1 pathway, a TUNEL assay was used for the detection of apoptotic cells in vitro and in vivo. The co­localization of neuron­specific nuclear protein and CC­3 was assessing using immunofluorescent staining. Pic improved neurological functions and ameliorated hippocampal neuronal pathology following CIRI. In addition, the expression levels of CC­3 and Bax and intracellular ROS levels were increased, while levels of antioxidant and non­enzymatic enzymes were decreased in the mouse model of CIRI. Low and high doses of Pic significantly decreased ROS production and the expression levels of apoptosis­related proteins, but increased antioxidant enzyme levels. However, a high­dose of Pic did not result in increased levels of non­enzymatic enzymes. Furthermore, low and high doses of Pic treatment significantly activated the Sirt1/FoxO1 pathway. Following inhibition of the Sirt1/FoxO1 pathway, the percentage of TUNEL­positive cells and expression of CC­3 were increased, and CC­3 was enriched in neurons. The antioxidant effects of Pic were blocked by inhibition of Sirt1 in vitro and in vivo. In conclusion, these results suggested that Pic may exert a neuroprotective effect against in hippocampal neurons via the Sirt1/FoxO1 pathway.

12.
Mol Med Rep ; 22(6): 5041-5052, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33174052

RESUMO

The authors' previous study demonstrated that miR­128 may exert an inhibitory effect on the osteogenic differentiation of bone marrow­derived mesenchymal stem cells (BM­MSCs), but its downstream mechanisms remain to be elucidated. The aim of the present study was to investigate the microRNA (miRNA/miR) and mRNA profiles of differentiated and undifferentiated BM­MSCs and explore new downstream targets for miR­128. The sequencing datasets of GSE107279 (miRNA) and GSE112318 (mRNA) were downloaded from the Gene Expression Omnibus database. The differentially expressed miRNAs (DEMs) and genes (DEGs) were identified using the DESeq2 method. The target genes of DEMs were predicted by the miRwalk 2.0 database. The hub target genes of miR­128 were screened by constructing the protein­protein interaction (PPI) network and module analysis. The expression levels of miR­128 and crucial target genes were validated by reverse transcription­quantitative (RT­q) PCR before or after transfection of miR­128 mimics to BM­MSCs. The miRNA expression profile analysis identified miR­128 as one of the significantly downregulated DEMs (total 338) in differentiated BM­MSCs compared with the undifferentiated control. A total of 103 predicted target genes of miR­128­3p were overlapped with upregulated DEGs. By calculating the topological properties of each protein in the PPI network, 6 upregulated genes (KIT, NTRK2, YWHAB, GAB1, AXIN1 and RUNX1; fold change was the highest for NTRK2) were considered to be hub genes. Of these, 4 were enriched in module 4 (RUNX1, KIT, GAB1 and AXIN1; RUNX1 was particularly crucial as it can interact with the others), while one was enriched in module 7 (YWHAB). The expression levels of miR­128 and these 6 target genes during the osteogenic differentiation were experimentally confirmed by RT­qPCR. In addition, the expression levels of these 6 genes were significantly reversed after transfection of miR­128­3p mimics into rat BM­MSCs compared with the miR­control group. These findings indicated that miR­128­3p may inhibit the osteoblast differentiation of BM­MSCs by downregulation of these 6 genes, particularly RUNX1, YWHAB and NTRK2.

13.
Vaccine ; 2020 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-33190947

RESUMO

BACKGROUND: A domestic human papillomavirus (HPV) vaccine, Cecolin, that protects against HPV strains 16 and 18 was introduced to the Chinese market at a relatively low price in May 2020.This study has explored Chinese women's perceptions of both domestic and imported HPV vaccines, which differ in price and valency. METHODS: Sentiment analysis and semantic network analyses were performed based on a sample of 45,729 domestic HPV vaccine-related posts from females on the Sina Weibo between April 17 and May 2, 2020. The geographic distribution was also analyzed based on the users' locations, which were retrieved from the database. RESULTS: Most of the posts were positive and neutral (85%), although 15% were negative (e.g., expressions of anger, sadness, fear and disgust). Semantic analyses of the negative posts revealed that Chinese women generally had positive attitudes towards the HPV vaccine and were willing to be vaccinated. However, obvious geographical variations were identified. Women who lived in economically developed areas expressed a stronger desire to obtain imported quadrivalent or nonavalent vaccines due to concerns regarding effectiveness and quality. The women expressed disgust and anger mainly regarding difficulties in making an appointment, age restrictions for the nonavalent vaccine and gender restrictions. However, the population targeted by the domestic vaccine, namely women who lived in economically undeveloped areas and had relatively low incomes, had a low awareness of the HPV vaccine. CONCLUSION: Government should provide programs, which educate females that bivalent HPV vaccine can offer protection against the majority of high-risk HPV types. Increasing awareness of the domestic vaccine among the population in economically undeveloped areas and provision of free domestic bivalent HPV vaccination/screening for low-income high-risk women would help to prevent cervical carcinoma. This issue also depends on rebuilding trust and repairing damage to the relationship between government/domestic vaccine manufacturers and the public.

14.
Mikrochim Acta ; 187(12): 653, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33175235

RESUMO

To simultaneously detect two metabolites of Aspergillus flavus, namely, cyclopiazonic acid (CPA) and aflatoxin (AFT), an ultrasensitive monoclonal antibody (mAb) YTT-2 against CPA was developed and characterized, with sensitivity to CPA of 1.32 ng mL-1. Along with the previously homemade mAb 1C11 against AFT, two mAbs were used to develop time-resolved fluorescence immunoprobes or gold immunoprobes. We developed two multiple-analyte paper immunosensors including time-resolved fluorescent immunochromatographic assay (TRFICA) and gold immunochromatographic assay (GICA) for the simultaneous determination of CPA and AFT. The TRFICA showed limits of determination (LODs) of 0.21 and 0.004 ng mL-1, while the GICA showed LODs of 0.33 and 0.01 ng mL-1 for CPA and AFT, respectively. To validate the specificity of the two rapid immunoassays, rice, corn and peanut samples were spiked with different concentrations of CPA and AFT. The two methods showed satisfactory recoveries (76.39~90.82% for CPA and 84.60~94.45% for AFT) and coefficients of variation of 3.50~7.80% for CPA and 4.12~13.90% for AFT. The results indicated that the TRFICA could complete the test within 5 min and had lower LODs and linear ranges, compared with that of GICA. The method developed in this work can be widely applied to the rapid and quantitative simultaneous determination of multiple harmful metabolites in fungi for food safety and health care. Graphical abstract.

15.
Hum Gene Ther ; 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33176492

RESUMO

Although colorectal cancer is the leading cause of death in patients with liver metastases, there are no efficient treatments available. Oncolytic virus therapy, a new type of tumour therapy, has become a potential solution. With the goal of improving the treatment of advanced colorectal cancer, we applied oHSV2 in a mouse model of colorectal cancer with liver metastasis. Compared with the control, oHSV2 effectively inhibited the growth of subcutaneous primary tumours, significantly reduced the number and size of liver metastases, and prolonged the median survival time of the mice. In addition, neutrophils, NK cells, T cells, B cells and cytokines in the tumour microenvironment and the body were all activated, and their frequencies increased significantly. Moreover, the proportion of immunosuppressive MDSCs decreased. oHSV2 treatment, which establishes an effective long-term antitumour immune response, is strongly resistant to rechallenge by the same tumour. Our data show that oHSV2 can effectively kill the primary tumour and attack distal and metastatic tumours by inducing immune responses, resulting in lasting antitumour efficacy and preventing tumour recurrence. It is believed that oHSV2 has good clinical application prospects.

16.
J Am Chem Soc ; 142(45): 19354-19359, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33140959

RESUMO

Spirocyclic hexadienones with multiple stereogenic centers are frequently found in natural products but remain challenging targets to synthesize. Herein, we report the enantioselective desymmetrization of bisphenol derivatives via Ir-catalyzed allylic dearomatization reactions, affording spirocyclic hexadienone derivatives with up to three contiguous stereogenic centers in good yields (up to 90%) and excellent enantioselectivity (up to 99% ee). The high efficiency of this reaction is exemplified by the short reaction time (30 min), low catalyst loading (down to 0.2 mol %), and ability to perform the reaction on a gram-scale. The total syntheses of (+)-tatanan B and (+)-tatanan C were also realized using this Ir-catalyzed allylic dearomatization reaction as a key step.

17.
J Am Chem Soc ; 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33174722

RESUMO

The first and asymmetric total synthesis of 4ß-acetoxyprobotryane-9ß,15α-diol, containing a rare and highly strained trans-fused bicyclo[3.3.0]octane ring system, has been achieved. The synthetically challenging [6-5-5] tricyclic ring system in the final product was efficiently and diastereoselectively synthesized via an asymmetric rhodium-catalyzed [4 + 2] cycloaddition reaction, followed by a unique benzilic acid type rearrangement under very mild conditions. The seven contiguous stereocenters were installed efficiently and diastereoselectively.

18.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 36(4): 336-339, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-33167094

RESUMO

OBJECTIVE: To investigate the effects of cyclic GMP-AMP synthase (cGAS) on the proliferation, migration and epithelial to mesenchymal transition (EMT) of breast cancer cells. METHODS: The cGAS lentiviral vector and control fluorescence vector were transfected into breast cancer MCF7 cells and were divided into negative group (NC) and MCF7-cGAS group. The effect of cGAS on proliferation in the MCF7 cells was detected by MTT. The effect of cGAS on cell migration was detected by Transwell assay. The expressions of EMT related proteins were analyzed by Western blot. RESULTS: After over-expressed with cGAS, the proliferation and migration of MCF7 cells were increased (P<0.05). The expression level of the epithelial markers E-cadherin was decreased, while the expression level of the mesenchymal markers N-cadherin was increased(P<0.05). CONCLUSION: The over-expression of cGAS increased the proliferation and migration of breast cancer cells and induced EMT in breast cancer cells.

19.
Artigo em Inglês | MEDLINE | ID: mdl-33170478

RESUMO

The aim of this study is to investigate the clinical features and outcome of interstitial lung disease (ILD)-onset rheumatoid arthritis (RA) and anti-citrullinated protein antibody (ACPA)-positive ILD-only patients. Arthritis-onset and ILD-onset RA-ILD and ACPA-positive ILD-only patients consecutively admitted to Peking Union Medical College Hospital from January 2008 to December 2017 were enrolled and followed-up. Their demographic, clinical, and laboratory features as well as outcome were collected and analyzed. Compared with arthritis-onset RA-ILD (n = 166, median arthritis-to-ILD interval: 60 months), the ILD-onset RA-ILD (n = 75, median ILD-to-arthritis interval: 2 months) had less rheumatoid nodules and higher titer of ACPA, and manifested more stable ILD (median estimated progression-free survival: 120 vs. 100 months, p = 0.019). Elder age (≥ 65 years) at ILD diagnosis and UIP pattern were associated with ILD progression by both univariate and Cox hazards modeling analysis (p < 0.05). In ACPA-positive ILD-only patients (n = 41), arthritis developed in 7 (17.1%) female patients after a median interval of 24 months. ACPA-positive ILD who subsequently developed arthritis exhibited higher frequency of rheumatoid factor (RF), higher titer of ACPA, and higher levels of ESR and CRP (p < 0.05). Multivariate regression analysis showed that positive RF (OR 12.55, 95% CI 1.31 to 120.48) was the independent risk factor for arthritis development in ACPA-positive ILD-only patients. ILD-onset RA-ILD had more stable ILD compared with arthritis-onset RA-ILD. ACPA-positive ILD patients with positive RF are at increased risk of developing RA.

20.
Rev Esp Enferm Dig ; 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33222481

RESUMO

testicular mixed germ cell tumor is characterized by high degree of malignancy and prone to metastasis, the common of which is retroperitoneal lymph node metastasis. At present, EUS has a very important diagnostic value for mediastinal, enterocoelia and retroperitoneal lymph node metastasis of malignant tumors. It also has a positive value for the space occupying of parenchyma or cavity organ and can be used for the puncture operation of multiple lesions under real-time ultrasound monitoring with high safety and small complications.

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