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1.
Artigo em Inglês | MEDLINE | ID: mdl-33813830

RESUMO

In this paper, we explore the acoustofluidic performance of zinc oxide (ZnO) thin-film surface acoustic wave (SAW) devices fabricated on flexible and bendable thin aluminum (Al) foils/sheets with thicknesses from 50 to 1500 µm. Directional transport of fluids along these flexible/bendable surfaces offers potential applications for the next generation of microfluidic systems, wearable biosensors and soft robotic control. Theoretical calculations indicate that bending under strain levels up to 3000 µÎµ causes a small frequency shift and amplitude change (<0.3%) without degrading the acoustofluidic performance. Through systematic investigation of the effects of the Al sheet thickness on the microfluidic actuation performance for the bent devices, we identify the optimum thickness range to both maintain efficient microfluidic actuation and enable significant deformation of the substrate, providing a guide to design such devices. Finally, we demonstrate efficient liquid transportation across a wide range of substrate geometries including inclined, curved, vertical, inverted, and lateral positioned surfaces using a 200 µm thick Al sheet SAW device.

2.
Chin J Integr Med ; 2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33881716

RESUMO

OBJECTIVE: To observe the clinical effect of penetrating moxibustion on migraine without aura (MO) patients. METHODS: Totally 60 MO patients from the Acupuncture Clinic of the Third Affiliated Hospital of Henan University of Chinese Medicine were collected from November 2015 to February 2017. All patients were assigned to a treatment group and a control group using a random number table, 30 cases in each group. The treatment group was treated with penetrating moxibustion, and the control group was treated with mild moxibustion, thrice a week for 4 consecutive weeks. The total effective rate, Visual Analogue Scale (VAS) scores, headache intensity, and Migraine Specific Quality of Life Questionnaire (MSQ) scores of patients after treatment were compared between the two groups. The moxibustion sensation and reaction after moxibustion were observed, and the adverse reactions were evaluated. All patients were followed up at 4 and 16 weeks after treatment. RESULTS: The total effective rate of the treatment group was significantly higher than that of the control group (93.33% vs. 80.00%, P<0.05). The improvement of VAS scores, headache intensity, and the role restrictive and role preventive scores in MSQ in the treatment group was better than those in the control group (P<0.05). The person-time of moxibustion sensations of itching, numbness and cold as well as flushing and sweating after moxibustion in the treatment group was all significantly higher than that in the control group (P<0.01). There was no significant difference in safety evaluation between the two groups (P>0.05). CONCLUSIONS: Penetrating moxibustion can significantly relieve pain and improve quality of life of MO patients. After penetrating moxibustion, flushing and sweating of patients were obvious, and the curative effect was superior to the mild moxibustion.

3.
Ying Yong Sheng Tai Xue Bao ; 32(4): 1250-1258, 2021 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-33899393

RESUMO

Moisture is an important factor affecting the priming effect of soil organic carbon (SOC). However, empirical evidence for its effect in mountain meadows soil is lacking. We conducted a 126-day laboratory incubation experiment with the high altitude (2130 m) mountain meadow soil in Wuyi Mountain, by adding 13C-labelled glucose combined with controlling soil moisture (30% and 60% of field water capacity, FWC). The CO2 concentration and 13C-CO2 abundance were measured regularly to examine the differences of SOC mineralization and priming effects under different water conditions and the driving factors. Our results showed that SOC mineralization rate increased with increasing soil water content. The priming effect of meadow soil with different soil moisture showed a decreasing trend with the increases of incubation time. The priming effect in soils with low FWC soil was significantly greater than that with high FWC. At the end of incubation, the cumulative priming effect of low FWC soil was 61.4% higher than that of high FWC soil. Compared with low FWC soil, high FWC soil released more CO2 from glucose, and the ratio of cumulative primed carbon to glucose mineralization under low FWC was significantly higher than that under high FWC soil, indicating that soil microorganisms under the high FWC condition might preferentially mineralize more glucose than SOC and consequently lower priming effect. Therefore, the priming effect under high FWC was smaller than that under low FWC. There was a significant positive relationship between priming effect and microbial biomass carbon, microbial biomass carbon/microbial biomass nitrogen, and NH4+-N, indicating that soil microbial biomass and composition could be changed under low FWC condition. The improved microbial "nitrogen-mining" would increase priming effect. Consequently, the decline of soil moisture of mountain meadow induced by global climate change may increase the priming effect of carbon, with consequences on carbon loss.


Assuntos
Carbono , Solo , Carbono/análise , China , Pradaria , Nitrogênio , Microbiologia do Solo
4.
Artigo em Inglês | MEDLINE | ID: mdl-33929956

RESUMO

Pedestrian detection is an important but challenging problem in computer vision, especially in human-centric tasks. Over the past decade, significant improvement has been witnessed with the help of handcrafted features and deep features. Here we present a comprehensive survey on recent advances in pedestrian detection. First, we provide a detailed review of single-spectral pedestrian detection that includes handcrafted features based methods and deep features based approaches. For handcrafted features based methods, we present an extensive review of approaches and find that handcrafted features with large freedom degrees in shape and space have better performance. In the case of deep features based approaches, we split them into pure CNN based methods and those employing both handcrafted and CNN based features. We give the statistical analysis and tendency of these methods, where feature enhanced, part-aware, and post-processing methods have attracted main attention. In addition to single-spectral pedestrian detection, we also review multi-spectral pedestrian detection, which provides more robust features for illumination variance. Furthermore, we introduce some related datasets and evaluation metrics, and a deep experimental analysis. We conclude this survey by emphasizing open problems that need to be addressed and highlighting various future directions. Researchers can track an up-to-date list at \url{https://github.com/JialeCao001/PedSurvey}.

5.
Orthop Surg ; 2021 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-33682337

RESUMO

The diagnostic potential of D-dimer and fibrinogen to detect periprosthetic joint infection (PJI) of the hip and knee is not well-understood. The aim of this study was to determine whether D-Dimer and fibrinogen can be used as effective biomarkers to screen PJI. A systematic review of the literature indexed in Web of Science, PubMed, Cochrane Library, Embase, and Google Scholar databases was performed. All studies using D-dimer levels in serum or plasma, or fibrinogen levels in plasma, for the diagnosis of PJI were included. Meta-analysis estimates, including sensitivity, specificity, diagnostic odds ratios (DOR), and the area under the summary receiver operating characteristic curve (AUSROC), were calculated using a random-effects model, and used to assess the diagnostic accuracy of these biomarkers. A total of nine studies were analyzed, and their quality was considered to be acceptable. D-dimer gave a limited diagnostic value if serum and plasma combined: sensitivity (0.77, 95% confidence interval [CI] [0.63 to 0.87]), specificity (0.67, 95% CI [0.54 to 0.78]), DOR (6.81, 95% CI [2.67 to 17.37]), and AUSROC (0.78, 95% CI [0.74 to 0.82]). Plasma D-dimer levels were associated with less satisfactory sensitivity (0.65, 95% CI 0.57 to 0.71), specificity (0.58, 95% CI 0.50 to 0.66), DOR (2.52, 95% CI 1.64 to 3.90), and AUSROC (0.65, 95% CI 0.61 to 0.69). Serum D-dimer levels showed higher corresponding values of 0.89 (95% CI 0.79 to 0.94), 0.76 (95% CI 0.55 to 0.89), 24.24 (95% CI 10.07 to 58.32), and 0.91 (95% CI 0.88 to 0.93). Plasma fibrinogen showed acceptable corresponding values of 0.79 (95% CI 0.70 to 0.85), 0.73 (95% CI 0.57 to 0.85), 10.14 (95% CI 6.16 to 16.70), and 0.83 (95% CI 0.79 to 0.86). Serum D-dimer may be an effective marker for the diagnosis of PJI in hip and knee arthroplasty patients, and it may show higher diagnostic potential than plasma fibrinogen. Plasma D-dimer may have limited diagnostic potential.

6.
J Ethnopharmacol ; 273: 114017, 2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-33716078

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Gynostemma pentaphyllum (Thunb.) Makino, a traditional medicine in China, has been widely used for the treatment of various diseases. Gypenoside LI (Gyp LI) is a major constituent from steamed G. pentaphyllum. Previous studies have shown that gypnenoside LI possess inhibitory effect on the growth of many cancer cells. However, its pharmacological effect in breast cancer and the mechanism have not been reported yet. AIM OF THE STUDY: To investigate the anti-breast cancer activity of gypenoside LI and underlying mechanisms of gypenoside LI in MDA-MB-231 and MCF-7 cells. MATERIAL/METHODS: The cytotoxicity of gypenoside LI was determined by MTT, colony-formation and three-dimensional spheroid assay. The migration, cell apoptosis and the cell cycle were investigated through cell morphology observation, flow cytometry analysis and key proteins detection. The anticancer mechanisms of gypenoside LI were detected by RNA sequencing (RNA-seq) and Gene Set Enrichment Analysis (GSEA) transcriptome analysis. RESULTS: Gypenoside LI inhibited cell proliferation, migration, induced cell apoptosis and cell cycle arrest. Gypenoside LI arrested cell cycle at G0/G1 phase by regulating E2F1. It also inhibited tumor proliferation by regulating the expression of ERCC6L. Interestingly, we found that E2F1 siRNA also down-regulated the expression of ERCC6L. Gypenoside LI showed potential anti-breast cancer cells activity, especially on triple-negative breast cancer cells. CONCLUSIONS: These data indicate that gypenoside LI could inhibit human breast cancer cells through inhibiting proliferation and migration, inducing apoptosis, arresting cell cycle at G0/G1 phase by regulating E2F1. It could be used as potential multi-target chemopreventive agents for cancer.

7.
Mil Med Res ; 8(1): 17, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33673879

RESUMO

BACKGROUND: Postoperative care has been evolving since the concept of enhanced recovery after surgery (ERAS) was introduced in China. This study aimed to evaluate the effects of early ambulation within 24 h after unilateral total knee arthroplasty (TKA) on postoperative rehabilitation and costs in a Chinese population. METHODS: This cohort study of patients with knee osteoarthritis who had undergone TKA at 24 large teaching hospitals between January 2014 and November 2016 involved 2687 patients who began ambulating within 24 h (Group A) and 3761 who began ambulating later than 24 h (Group B). The outcome measurements, such as length of stay (LOS), total hospitalization costs, dynamic pain level, knee flexion range of motion (ROM), results of the 12-Item Short Form Survey (SF-12), incidence of thromboembolic events and other complications, were recorded and compared. RESULTS: The early ambulation group (Group A) had a shorter LOS and lower hospitalization costs and pain levels than the late ambulation group (Group B). There was a favorable effect in enhancing ROM for patients in Group A compared with patients in Group B. In Group A, patients had significantly higher postoperative SF-12 scores than those in Group B. The incidence of deep venous thrombosis (DVT) and pulmonary infection was significantly lower in Group A than in Group B. The incidence of pulmonary embolism (PE) and other complications did not differ between the two groups. CONCLUSION: Early ambulation within 24 h after TKA was associated with reduced LOS, improved knee function, lower hospitalization costs and lower incidence of DVT and pulmonary infection in the Chinese population.


Assuntos
Artroplastia do Joelho/métodos , Deambulação Precoce/normas , Idoso , China , Estudos de Coortes , Deambulação Precoce/enfermagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
8.
BMC Genomics ; 22(1): 164, 2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33750298

RESUMO

BACKGROUND: Only 1.5% of the human genome encodes proteins, while large part of the remaining encodes noncoding RNAs (ncRNA). Many ncRNAs form structures and perform many important functions. Accurately identifying structured ncRNAs in the human genome and discovering their biological functions remain a major challenge. RESULTS: Here, we have established a pipeline (CM-line) with the following features for analyzing the large genomes of humans and other animals. First, we selected species with larger genetic distances to facilitate the discovery of covariations and compatible mutations. Second, we used CMfinder, which can generate useful alignments even with low sequence conservation. Third, we removed repetitive sequences and known structured ncRNAs to reduce the workload of CMfinder. Fourth, we used Infernal to find more representatives and refine the structure. We reported 11 classes of structured ncRNA candidates with significant covariations in humans. Functional analysis showed that these ncRNAs may have variable functions. Some may regulate circadian clock genes through poly (A) signals (PAS); some may regulate the elongation factor (EEF1A) and the T-cell receptor signaling pathway by cooperating with RNA binding proteins. CONCLUSIONS: By searching for important features of RNA structure from large genomes, the CM-line has revealed the existence of a variety of novel structured ncRNAs. Functional analysis suggests that some newly discovered ncRNA motifs may have biological functions. The pipeline we have established for the discovery of structured ncRNAs and the identification of their functions can also be applied to analyze other large genomes.

9.
Artigo em Inglês | MEDLINE | ID: mdl-33655631

RESUMO

Lithium (Li) metal anodes hold great promise for next-generation high-energy-density batteries, while the insufficient fundamental understanding of the complex solid electrolyte interphase (SEI) is the major obstacle for the full demonstration of their potential in working batteries. The characteristics of SEI highly depend on the inner solvation structure of lithium ions (Li+ ). Herein, we clarify the critical significance of cosolvent properties on both Li+ solvation structure and the SEI formation on working Li metal anodes. Non-solvating and low-dielectricity (NL) cosolvents intrinsically enhance the interaction between anion and Li+ by affording a low dielectric environment. The abundant positively charged anion-cation aggregates generated as the introduction of NL cosolvents are preferentially brought to the negatively charged Li anode surface, inducing an anion-derived inorganic-rich SEI. A solvent diagram is further built to illustrate that a solvent with both proper relative binding energy toward Li+ and dielectric constant is suitable as NL cosolvent.

10.
Chem Commun (Camb) ; 57(29): 3587-3590, 2021 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-33710227

RESUMO

We propose a novel strategy to introduce platinum into the metal nodes of ZIF-8 by preloading Pt as a dopant in ZnO (Pt-ZnO) and then convert it to Pt doped ZIF-8 (Pt-ZIF-8) through a chemical vapor deposition (CVD) approach. The solvent-free conversion of Pt-ZnO to Pt-ZIF-8 allows the Pt dopant in ZnO to coordinate with organic linkers directly without the formation of Pt nanoparticles, which is a general issue of many methods. This general synthesis strategy may facilitate the discovery of MMOFs that have not been reported previously.

11.
J Ethnopharmacol ; 271: 113907, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33556477

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Gynostemma pentaphyllum (Thunb.) Makino is a traditional medicine commonly used in China, East Asia and Southeast Asia. In clinic, it is mainly used for hyperlipidemia and antitumor. Its antitumor activity was first recorded in "Illustrated Catalogue of Plants". Gypenosides were the main active ingredients of G. pentaphyllum. The anticancer activity of gypenosides in vivo and in vitro had been widely reported. However, the mechanism of gypenosides in renal cell carcinoma (RCC) still unclear. AIM OF THE STUDY: In this study, we tried to investigate the active constituents from G. pentaphyllum and potential mechanisms in RCC treatment through network pharmacology and in vitro experiments. MATERIAL/METHODS: Active compounds and their targets were evaluated and screened through TCMSP and Swiss Target Prediction database. Notably, nine preliminary screened components obtained from database were identified by LC-MS and LC-MS/MS. The targets associated with RCC were obtained from OMIM, TTD and GeneCards database. The PPI network and active component/target/pathway networks were constructed to identify the potential drug targets using String database and Cytoscape software. The functions and pathways of targets were analyzed through DAVID database. Finally, AutoDockTools 1.5.6 was used for molecular docking to assess the binding ability between compounds and targets. To support our prediction, we then explore the antitumor effect and mechanism of gypenosides by vitro experiments. CCK8 and flow cytometry were performed to evaluate cell death treated with gypenosides. Quantitative real-time PCR and Western blot were conducted to detect the changes of PI3K/AKT/mTOR signaling pathway. RESULTS: Nine saponins and 68 targets have been screened. The hub targets covered PIK3CA, VEGFA, STAT3, JAK2, CCND1 and MAPK3. Enrichment analysis showed that the pathways mainly contained PI3K/Akt/mTOR, HIF-1, TNF, JAK-STAT and MAPK signaling pathways. Gypenosides extracted from G. pentaphyllum showed strong activity against 786-O and Caki-1 cells, and cell apoptosis were detected through Annexin V/PI dual staining assay. RT-qPCR showed that gypenosides downregulated the levels of PIK3CA, Akt and mTOR in Caki-1 and 786-O cells. Mechanistically, gypenosides induced apoptosis of RCC cells through regulating PI3K/Akt/mTOR signaling pathway which was implemented though decreasing the phosphorylation level of Akt and mTOR. CONCLUSIONS: Gypenosides induced apoptosis of RCC cells by modulating PI3K/Akt/mTOR signaling pathway.

12.
J Thromb Haemost ; 19(4): 1038-1048, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33534149

RESUMO

BACKGROUND: High incidence of asymptomatic venous thromboembolism (VTE) has been observed in severe COVID-19 patients, but the characteristics of symptomatic VTE in general COVID-19 patients have not been described. OBJECTIVES: To comprehensively explore the prevalence and reliable risk prediction for VTE in COVID-19 patients. METHODS/RESULTS: This retrospective study enrolled all COVID-19 patients with a subsequent VTE in 16 centers in China from January 1 to March 31, 2020. A total of 2779 patients were confirmed with COVID-19. In comparison to 23,434 non-COVID-19 medical inpatients, the odds ratios (ORs) for developing symptomatic VTE in severe and non-severe hospitalized COVID-19 patients were 5.94 (95% confidence interval [CI] 3.91-10.09) and 2.79 (95% CI 1.43-5.60), respectively. When 104 VTE cases and 208 non-VTE cases were compared, pulmonary embolism cases had a higher rate for in-hospital death (OR 6.74, 95% CI 2.18-20.81). VTE developed at a median of 21 days (interquartile range 13.25-31) since onset. Independent factors for VTE were advancing age, cancer, longer interval from symptom onset to admission, lower fibrinogen and higher D-dimer on admission, and D-dimer increment (DI) ≥1.5-fold; of these, DI ≥1.5-fold had the most significant association (OR 14.18, 95% CI 6.25-32.18, p = 2.23 × 10-10 ). A novel model consisting of three simple coagulation variables (fibrinogen and D-dimer levels on admission, and DI ≥1.5-fold) showed good prediction for symptomatic VTE (area under the curve 0.865, 95% CI 0.822-0.907, sensitivity 0.930, specificity 0.710). CONCLUSIONS: There is an excess risk of VTE in hospitalized COVID-19 patients. This novel model can aid early identification of patients who are at high risk for VTE.


Assuntos
Biomarcadores/sangue , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Tromboembolia Venosa/diagnóstico , Trombose Venosa/epidemiologia , Idoso , /diagnóstico , China/epidemiologia , Feminino , Mortalidade Hospitalar , Humanos , Imunização Passiva , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Tromboembolia Venosa/sangue , Tromboembolia Venosa/epidemiologia , Tromboembolia Venosa/etiologia , Trombose Venosa/sangue , Trombose Venosa/etiologia
13.
Commun Biol ; 4(1): 257, 2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33637968

RESUMO

Self-complementing split fluorescent proteins (split FP1-10/11) have become an important labeling tool in live-cell protein imaging. However, current split FP systems to label multiple proteins in single cells have a fundamental limitation in the number of proteins that can be simultaneously labeled. Here, we describe an approach to expand the number of orthogonal split FP systems with spectrally distinct colors. By combining rational design and cycles of directed evolution, we expand the spectral color palette of FP1-10/11. We also circularly permutate GFP and synthesize the ß-strand 7, 8, or 10 system. These split GFP pairs are not only capable of labeling proteins but are also orthogonal to the current FP1-10/11 pairs, offering multiplexed labeling of cellular proteins. Our multiplexing approach, using the new orthogonal split FP systems, demonstrates simultaneous imaging of four distinct proteins in single cells; the resulting images reveal nuclear localization of focal adhesion protein Zyxin.

14.
J Biochem Mol Toxicol ; 35(4): e22719, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33501684

RESUMO

Leukemia is amongst the cancers accountable for substantial mortality around the world. Tomentosin is a bioactive compound with a pharmacological significance, and its anticancer property against human leukemia MOLT-4 cell line has never been reported. Hence, the objective of this study was to explore the anticancer activity of tomentosin in MOLT-4 human leukemia cells. In the current investigation, the cytotoxic effects of tomentosin ensuing potent toxicity (IC50 : 10 µM) in MOLT-4 cells after incubation at 24 h have been presented. Furthermore, tomentosin triggered intracellular reactive oxygen species production and showed the induction of intrinsic/mitochondrial pathways in treated MOLT-4 cells, revealing a significant cytotoxicity activity. Also, fluorescent microscopic studies using acridine orange/ethidium bromide and propidium iodide staining confirmed the occurrence of apoptosis in tomentosin-treated MOLT-4 cells. Quantitative reverse transcription polymerase chain reaction presented a negative regulation of cyclin D1 and BcL-2 expression and a positive regulated BAX and caspase-3 messenger RNA expression in tomentosin-treated MOLT-4 cells. Tomentosin further inhibited the inflammatory transcription factors such as nuclear factor κB (NF-κB), tumor necrosis factor α, interleukin 1ß (IL-1ß), and IL-6. Additionally, inhibition of the m-TOR/PI3K/AKT protein expression by tomentosin in MOLT-4 cells was confirmed. Overall, these findings lead to a conclusion that tomentosin induces apoptosis in MOLT-4 cells through caspase-facilitated proapoptotic pathway, and inhibition of the NF-κB-stimulated Bcl-2 facilitated the antiapoptotic pathway.

15.
Chem Rev ; 2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33492123

RESUMO

Within the wide family of gold-catalyzed reactions, gold photocatalysis intrinsically features unique elementary steps. When gold catalysis meets photocatalysis, a valence change of the gold center can easily be achieved via electron transfer and radical addition, avoiding the use of stoichiometric sacrificial external oxidants. The excellent compatibility of radicals with gold catalysts opens the door to a series of important organic transformations, including redox-neutral C-C and C-X coupling, C-H activation, and formal radical-radical cross-coupling. The photocatalysis with gold complexes nicely complements the existing photoredox catalysis strategies and also opens a new avenue for gold chemistry. This review covers the achieved transformations for both mononuclear gold(I) catalysts (with and without a photosensitizer) and dinuclear gold(I) photocatalysts. Various fascinating methodologies, their value for organic chemists, and the current mechanistic understanding are discussed. The most recent examples also demonstrate the feasibility of both, mononuclear and dinuclear gold(I) complexes to participate in excited state energy transfer (EnT), rather than electron transfer. The rare applications of gold(III) photocatalysts, both homogeneous and heterogeneous, are also summarized.

17.
IEEE Trans Image Process ; 30: 207-219, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33141669

RESUMO

Vehicles, pedestrians, and riders are the most important and interesting objects for the perception modules of self-driving vehicles and video surveillance. However, the state-of-the-art performance of detecting such important objects (esp. small objects) is far from satisfying the demand of practical systems. Large-scale, rich-diversity, and high-resolution datasets play an important role in developing better object detection methods to satisfy the demand. Existing public large-scale datasets such as MS COCO collected from websites do not focus on the specific scenarios. Moreover, the popular datasets (e.g., KITTI and Citypersons) collected from the specific scenarios are limited in the number of images and instances, the resolution, and the diversity. To attempt to solve the problem, we build a diverse high-resolution dataset (called TJU-DHD). The dataset contains 115354 high-resolution images (52% images have a resolution of 1624×1200 pixels and 48% images have a resolution of at least 2, 560×1.440 pixels) and 709 330 labeled objects in total with a large variance in scale and appearance. Meanwhile, the dataset has a rich diversity in season variance, illumination variance, and weather variance. In addition, a new diverse pedestrian dataset is further built. With the four different detectors (i.e., the one-stage RetinaNet, anchor-free FCOS, two-stage FPN, and Cascade R-CNN), experiments about object detection and pedestrian detection are conducted. We hope that the newly built dataset can help promote the research on object detection and pedestrian detection in these two scenes. The dataset is available at https://github.com/tjubiit/TJU-DHD.

18.
Nat Chem ; 13(2): 182-190, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33318674

RESUMO

Transition-metal-catalysed, redox-neutral dehydrosilylation of alkenes is a long-standing challenge in organic synthesis, with current methods suffering from low selectivity and narrow scope. In this study, we report a general and simple method for the manganese-catalysed dehydrosilylation and hydrosilylation of alkenes, with Mn2(CO)10 as a catalyst precursor, by using a ligand-tuned metalloradical reactivity strategy. This enables versatility and controllable selectivity with a 1:1 ratio of alkenes and silanes, and the synthetic robustness and practicality of this method are demonstrated using complex alkenes and light olefins. The selectivity of the reaction has been studied using density functional theory calculations, showing the use of an iPrPNP ligand to favour dehydrosilylation, while a JackiePhos ligand favours hydrosilylation. The reaction is redox-neutral and atom-economical, exhibits a broad substrate scope and excellent functional group tolerance, and is suitable for various synthetic applications on a gram scale.

19.
Chem Soc Rev ; 50(3): 1874-1912, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33315028

RESUMO

Gold chemistry has developed extensively in the past decade, and a dozen good reviews have been presented discussing this progress. Few however have paid close attention to the progress in organic synthesis of dinuclear gold-catalysis. A dinuclear gold catalyst is defined here as a gold complex with two gold centers linked by a bidentate ligand. With theoretical analysis and some representative studies in recent years, this comprehensive review highlights the particular properties of dinuclear gold-complexes, especially aurophilic interactions, and systematically summarizes the recent achievements of dinuclear gold-catalyzed coupling reactions, asymmetric catalysis, and photocatalysis, where dinuclear gold catalysts tend to show a greater advantage than the mononuclear gold catalysts.

20.
Int J Pharm ; 594: 120182, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33346126

RESUMO

The objective of this study is to use a carbohydrate polymer deacetylated gellan gum (DGG) as matrix to design nanocrystals based intranasal in situ gel (IG) for nose-to -brain delivery of drug. The harmine nanocrystals (HAR-NC) as model drug were prepared by coupling homogenization and spray-drying technology. The HAR-NC was redispersed in the (DGG) solutions and formed the ionic-triggered harmine nanocrystals based in situ gel (HAR-NC-IG). The crystal state of HAR remained unchanged during the homogenization and spray-drying. And the HAR-NC-IG with 0.5% DGG exhibited excellent in situ-gelation ability, water retention property and in vitro release behavior. The bioavailability in brain of intranasal HAR-NC-IG were 25-fold higher than that of oral HAR-NC, which could be attributed to nanosizing effect of HAR-NC and bioadhesive property of DGG triggered by nasal fluid. And the HAR-NC-IG could significantly inhibit the expression of acetylcholinesterase (AchE) and increase the content of acetylcholin (ACh) in brain compared with those of reference formulations (p < 0.01). The DGG based nanocrystals-in situ gel was a promising carrier for nose-to-brain delivery of poorly soluble drug, which could prolong the residence time and improve the bioavailability of poorly soluble drugs in brain.

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