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1.
Nat Commun ; 11(1): 664, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32005840

RESUMO

Two-dimensional hybrid organic-inorganic perovskites with strongly bound excitons and tunable structures are desirable for optoelectronic applications. Exciton transport and annihilation are two key processes in determining device efficiencies; however, a thorough understanding of these processes is hindered by that annihilation rates are often convoluted with exciton diffusion constants. Here we employ transient absorption microscopy to disentangle quantum-well-thickness-dependent exciton diffusion and annihilation in two-dimensional perovskites, unraveling the key role of electron-hole interactions and dielectric screening. The exciton diffusion constant is found to increase with quantum-well thickness, ranging from 0.06 ± 0.03 to 0.34 ± 0.03 cm2 s-1, which leads to long-range exciton diffusion over hundreds of nanometers. The exciton annihilation rates are more than one order of magnitude lower than those found in the monolayers of transition metal dichalcogenides. The combination of long-range exciton transport and slow annihilation highlights the unique attributes of two-dimensional perovskites as an exciting class of optoelectronic materials.

2.
Trials ; 21(1): 110, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992367

RESUMO

BACKGROUND: Many studies have shown the potential therapeutic effect of acupuncture on allergic rhinitis. Most of these studies were limited by low-quality evidence. Preliminary experiments showed that the use of acupuncture at three nasal acupoints plus acupoint application (AAP) achieves a more persistent effect in the treatment of perennial allergic rhinitis than acupuncture alone. In this study, a multicenter, single-blind, randomized controlled trial will be performed, in which acupuncture at nonmeridian acupoints and sham AAP will be used as the control group to evaluate the effect of AAP through long-term observation. METHODS: The trial is designed on the basis of the Consolidated Standards of Reporting Trials 2010 guidelines and Standards for Reporting Interventions in Controlled Trials of Acupuncture. A total of 120 participants with perennial allergic rhinitis will be randomly assigned to a treatment or control group. A specially appointed investigator will be in charge of randomization. The participants in the treatment group will be treated with acupuncture at EX-HN3, LI20, and EX-HN8 thrice per week for a total of 12 sessions. In addition, they will undergo AAP at DU14, BL13, EX-BI, and RN22. The participants in the control group will be treated with sham AAP. The primary outcome will be the change in the Total Nasal Symptom Score from baseline to the completion of 4-week treatment. Secondary outcomes include changes in visual analog scale and total non-nasal symptom scores from baseline to the second and fourth weeks of treatment, as well as 1, 3, and 6 months after the completion of treatment. Peripheral blood IL-4, IL-5, IL-6, IL-8, and IL-10 levels will be measured, and any side effects related to treatment will be observed and recorded. DISCUSSION: It is expected that this randomized clinical trial will provide evidence to determine the effects of AAP compared with acupuncture at nonmeridian acupoints and sham AAP, particularly the long-term effect. These findings will help improve the clinical application of this technique. TRIAL REGISTRATION: Acupuncture-Moxibustion Clinical Trial Registry AMCTR-ICR-18000179. Registered on 12 April 2018.

3.
J Pharm Biomed Anal ; 177: 112844, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31491659

RESUMO

Traditionally, for a liquid chromatography tandem mass spectrometry (LC-MS/MS) bioanalytical assay, an external calibration curve is required to achieve accurate quantitation of an analyte. Recently, a novel in-sample calibration curves (ISCC) methodology that can achieve quick and accurate LC-MS/MS bioanalysis without the use of an external calibration curve was reported. The ISCC methodology utilizes the presence of multiple naturally occurring isotopologues of a stable isotopically labeled analyte to construct an in-sample calibration curve for the quantification. This methodology has great potential in many applications, for example biomarker measurement, quantitative proteomics and clinical diagnosis. Here, we assessed the feasibility of applying this ISCC-LC-MS/MS methodology in regulated bioanalysis using BMS-984478, a drug candidate, as the model compound. We also proposed method validation procedures/processes for this new approach for industry peers' consideration and feedback. A LC-MS/MS method using the ISCC strategy was successfully developed and validated for the quantitative analysis of BMS-984478 in human plasma over the range of 1.33-993.42 ng/mL. The validated ISCC-LC-MS/MS method was compared with a previously validated method using the conventional external calibration curve approach, and the two methods showed equivalent performance. Critical considerations and practical approaches in method development, validation and sample analysis were also discussed. Our work demonstrated that the ISCC-LC-MS/MS methodology is a promising approach for regulated LC-MS/MS bioanalysis. ISCC-LC-MS/MS methodology has its unique advantages and has great potential to be widely applied for various quantitative applications, and may even change the landscape of quantitative analysis.


Assuntos
Antivirais/isolamento & purificação , Fracionamento Químico/métodos , Espectrometria de Massas em Tandem/métodos , Antivirais/administração & dosagem , Antivirais/sangue , Calibragem , Cromatografia Líquida/métodos , Estudos de Viabilidade , Humanos , Limite de Detecção , Padrões de Referência , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas por Ionização por Electrospray/normas , Espectrometria de Massas em Tandem/normas
4.
Cancer Cell Int ; 19: 322, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31827396

RESUMO

Background: Autologous tumor-infiltrating lymphocytes (Tils) immunotherapy is a promising treatment in patients with advanced hepatocellular cancer. Although Tils treatment has shown great promise, their persistence and the efficacy after adoptive-transfer are insufficient and remain a challenge. Studies have demonstrated that IL-15 and Akt inhibitor can regulate T cell differentiation and memory. Here, we constructed S-15 (Super human IL-15), a fusion protein consisting of human IL-15, the sushi domain of the IL-15 receptor α chain and human IgG-Fc. Herein we compared the effects of S-15 with IL-2 or in combination with Akti on the expansion and activation of Tils. Methods: Hepatocellular cancer tissues were obtained from 6 patients, Tils were expanded using IL-2, IL-2/S-15, IL-2/Akti or in combination IL-2/S-15/Akti. At day 10, anti-CD3 antibody was added to the culture media and expanded to day 25. The composition, exhaustion and T-cell differentiation markers (CD45RA/CCR7) were analyzed by flow cytometry. Results: We found that IL-2/S-15/Akti expanded Tils and showed the highest percentage of central memory CD45RA-CCR7+ phenotype prior to anti-CD3 antibody activation and after anti-CD3 antibody activation. T cells cultured with IL-2/S-15/Akti exhibited a mixture of CD4+, CD8+, and CD3+CD4-CD8- T cells; S-15 in combination with Akt inhibitor downregulated the expression of PD-1+Tim-3+ on Tils and decreased the Tregs in Tils. Additionally, the Tils expanded in the presence of the Akt inhibitor and S-15 showed enhanced antitumor activity as indicated by the increase in IFN-γ producing tumor infiltrating CD8+ T cells and without comprising the Tils expansion. Conclusion: Our study elucidates that IL-2/S-15/Akti expanded Tils and represent a viable source for the cellular therapy for patients with hepatocellular cancer.

5.
Zhongguo Zhong Yao Za Zhi ; 44(22): 4975-4984, 2019 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-31872608

RESUMO

Databases including CNKI,Wan Fang,CBM,VIP,PubMed and Cochrane Library were searched to collect qualified researches,and the quality of articles was evaluated according to scales. Meta-analysis including subgroup analysis was performed by using Rev Man 5. 3 software and Meta-regression test was performed by using Stata 12. 0 software. All of these methods were used to systematically evaluate the safety and clinical efficacy of Qili Qiangxin Capsules in treatment of ischemic heart failure under two circumstances( with or without syndrome differentiation). A total of 22 randomized controlled trials( RCTs) involving 1 942 patients were included,with generally low quality. RESULTS: of Meta-analysis showed that as compared with the routine Western treatment alone,additional use of Qili Qiangxin Capsules could improve the clinical efficacy( RR = 1. 21,95%CI[1. 16,1. 27],P<0. 000 01) in treatment of ischemic heart failure,with its combined effect of syndrome differentiation group greater than that of non-syndrome differentiation group( P= 0. 03,I~2= 78. 9%),Meta-regression( sig = 0. 9,P = 0. 057); left ventricular ejection fraction( WMD = 7. 28,95% CI[5. 18,9. 38],P<0. 000 01),with combined effect of syndrome differentiation group greater than that of non-syndrome differentiation group( P= 0. 01,I2= 83. 2%),Meta-regression( I~2= 81. 09%,R2= 29. 08%,sig = 0. 47,P = 0. 029); 6-minute walk test( WMD = 33. 20,95%CI[24. 70,41. 70 ],P < 0. 000 01); left ventricular end diastolic diameter( WMD =-4. 61,95% CI[-5. 38,-3. 84 ],P <0. 000 01); left ventricular end diastolic volume( WMD =-34. 43,95%CI[-38. 81,-30. 05],P< 0. 000 01); and left ventricular end systolic volume( WMD =-9. 60,95% CI[-13. 16,-6. 05],P < 0. 000 01). Adverse effects were reported in 11 patients taking Qili Qiangxin Capsules and in 20 patients with routine treatment group,tolerable in both groups. None of the patients had obvious abnormality in liver and kidney function. Qili Qiangxin Capsules were effective and safe in the treatment of ischemic heart failure,which can further improve clinical efficacy as compared with routine treatment alone. Qili Qiangxin Capsules with syndrome differentiation showed more significant effects than those without syndrome differentiation,indicating better efficacy of clinical syndrome differentiation. However,these conclusions still need to be verified with more high-quality and large-sample literature.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Cápsulas , Humanos , Masculino , Síndrome
6.
Langmuir ; 35(47): 15131-15136, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31682456

RESUMO

The synthesis of intermetallic antimonides usually depends on either the high-temperature alloying technique from high-purity metals or the flux method in highly poisonous Pb-melt. In this paper, we introduced a soft-chemical method to synthesize intermetallic antimonides from ternary chalcogenide precursors under an argon atmosphere below 200 °C. Powder X-ray diffraction and compositional analysis clearly indicate that a new phase of the Ag3Sb nanocrystal was synthesized from the Ag3SbS3 precursors. Three types of trialkylphosphines (TAPs) were applied as desulfurization agents, and the transformation mechanism was elucidated. The capability of the desulfurization agent follows the sequence of triphenylphosphine (TPP) > tributylphosphine (TBP) > trioctylphosphine (TOP). Besides, this TAP-driven desulfurization route to synthesize the intermetallic phase could also be possible for AgSbSe2 and Sb2S3. Therefore, this paper provides an efficient and mild technique for the fabrication of intermetallic nanocrystals.

7.
ChemMedChem ; 14(22): 1933-1939, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31696673

RESUMO

In this work, we designed a prodrug that reacts with cellular oxidative equivalents leading to ether cleavage and cyclization to release an active phosphatidylinositol 3-kinase (PI3K) inhibitor. We show that the compound reduces affinity for PI3KA relative to the PI3K inhibitor, is slow to intercellularly oxidize, and is resistant to liver microsomes. We observed modest activity in untreated acute myeloid leukemia cells and 14-fold selectivity relative to non-cancerous cells. The cellular activity of the compound can be modulated by the addition of antioxidants or oxidants, indicating the compound activity is sensitive to cellular reactive oxygen species (ROS) state. Co-treatment with cytosine arabinoside or doxorubicin was used to activate the compound inside cells. We observed strong synergistic activity specifically in acute myeloid leukemia (AML) cancer cells with an increase in selective anticancer activity of up to 90-fold. Thus, these new self-cyclizing compounds can be used to increase the selectivity of anticancer agents.

8.
Stem Cell Res Ther ; 10(1): 331, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31747966

RESUMO

BACKGROUND: Experimental and clinical trials have demonstrated the efficiency of bone marrow-derived mesenchymal stromal/stem cells (bMSCs) in the treatment of myocardial infarction. However, after intravenous injection, the ineffective migration of engrafted bMSCs to the hearts remains an obstacle, which has an undesirable impact on the efficiency of cell-based therapy. Therefore, we attempted to identify a marker that could distinguish a subpopulation of bMSCs with a promising migratory capacity. METHODS: Here, CD51-negative and CD51-positive cells were isolated by flow cytometry from Ter119-CD45-CD31-bMSCs and cultured in specifically modified medium. The proliferation ability of the cells was evaluated by 5-ethynyl-2'-deoxyuridine (EdU) staining or continuously monitored during culture, and the differentiation potential was assessed by culturing the cells in the appropriate conditioned media. Wound healing assays, transwell assays and quantitative polymerase chain reaction (qPCR) were used to measure the migratory ability. The mice were subjected to a sham operation or myocardial infarction (MI) by permanently occluding the coronary artery, and green fluorescent protein (GFP)-labelled cells were transplanted into the mice via intravenous infusion immediately after MI. Heart function was measured by echocardiography; infarct myocardium tissues were detected by triphenyl tetrazolium chloride (TTC) staining. Additionally, immunofluorescence staining was used to verify the characteristics of CD51+bMSCs and inflammatory responses in vivo. Statistical comparisons were performed using a two-tailed Student's t test. RESULTS: In this study, the isolated CD51-bMSCs and CD51+bMSCs, especially the CD51+ cells, presented a favourable proliferative capacity and could differentiate into adipocytes, osteocytes and chondrocytes in vitro. After the cells were transplanted into the MI mice by intravenous injection, the therapeutic efficiency of CD51+bMSCs in improving left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) was better than that of CD51-bMSCs. Compared with CD51-bMSCs, CD51+bMSCs preferentially migrated to and were retained in the infarcted hearts at 48 h and 8 days after intravenous injection. Accordingly, the migratory capacity of CD51+bMSCs exceeded that of CD51-bMSCs in vitro, and the former cells expressed higher levels of chemokine receptors or ligands. Interestingly, the retained CD51+bMSCs retained in the myocardium possessed proliferative potential but only differentiated into endothelial cells, smooth muscle cells, fibroblasts or cardiomyocytes. Transplantation of CD51+bMSCs partially attenuated the inflammatory response in the hearts after MI, while the potential for inflammatory suppression was low in CD51-bMSC-treated mice. CONCLUSIONS: These findings indicated that the CD51-distinguished subpopulation of bMSCs facilitated proliferation and migration both in vitro and in vivo, which provided a novel cell-based strategy to treat acute MI in mice by intravenous injection.

9.
Colloids Surf B Biointerfaces ; 184: 110494, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31520997

RESUMO

Nanoparticles are nanocrystals with complex facets and defective structures that do not adopt an idealised shape. Various physicochemical parameters of nanoparticles, such as surface composition, size, and stiffness, can regulate differentiation in mesenchymal stem cells (MSCs), but the influence of shapes with many edges and corner regions has not been investigated. Herein, we investigated the effects of two gold nanostructures modified with 11-mercaptoundecanoic acid, namely gold nanocubes (MUA-AuNCs) and nanooctahedras (MUA-AuNOs), on viability and differentiation in rat bone marrow MSCs (bMSCs). Analysis of cytotoxicity and proliferation demonstrated good biocompatibility, with concentrations <100 µg·mL-1 not significantly different from untreated controls. Alkaline phosphatase activity and Alizarin Red S staining revealed weaker potential for bMSCs to differentiate into osteoblasts following treatment with both low (5 µg·mL-1) and high (25 µg·mL-1) concentrations of the gold nanostructures. By contrast, Oil Red O staining showed that both nanostructures enhanced adipogenic differentiation, and upregulated peroxisome proliferator-activated receptor gamma (PPARγ) and fatty acid binding protein-4 (Fabp4) expression at both mRNA and protein levels. The effects on differentiation were both structure- and dose-dependent; MUA-AuNOs were more effective for enhancing adipogenic differentiation and weakening osteogenic differentiation, possibly due to generating higher levels of reactive oxygen species (ROS). These findings lay the foundation for using these nanoparticles as ex vivo labels in MSC-based imaging and therapy.

10.
Artigo em Inglês | MEDLINE | ID: mdl-31546765

RESUMO

The waste generation rate (WGR) is used to predict the generation of construction and demolition waste (C&DW) and has become a prevalent tool for efficient waste management systems. Many studies have focused on deriving the WGR, but most focused on demolition waste rather than construction waste (CW). Moreover, previous studies have used theoretical databases and thus were limited in showing changes in the generated CW during the construction period of actual sites. In this study, CW data were collected for recently completed apartment building sites through direct measurement, and the WGR was calculated by CW type for the construction period. The CW generation characteristics by type were analyzed, and the results were compared with those of previous studies. In this study, CW was classified into six types: Waste concrete, waste asphalt concrete, waste wood, waste synthetic resin, waste board, and mixed waste. The amount of CW generated was lowest at the beginning of the construction period. It slowly increased over time and then decreased again at the end. In particular, waste concrete and mixed waste were generated throughout the construction period, while other CWs were generated in the middle of the construction period or towards the end. The research method and results of this study are significant in that the construction period was considered, which has been neglected in previous studies on the WGR. These findings are expected to contribute to the development of efficient CW management systems.


Assuntos
Materiais de Construção/estatística & dados numéricos , Habitação/estatística & dados numéricos , Gerenciamento de Resíduos/métodos , Gerenciamento de Resíduos/estatística & dados numéricos , República da Coreia
12.
Chem Commun (Camb) ; 55(70): 10412-10415, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31403632

RESUMO

In this study, Ge0.90Ga0.10 nano-twists were prepared by an in situ Ga-alloying method to inhibit the fractal growth of Ge. The mobility of Li+ in the Ge0.90Ga0.10 nano-twists was two orders higher than that in Ge. This advantage promotes fast charging of Li-ion batteries with the rate capability of 819 mA h g-1 at 16 A g-1.

13.
J Phys Chem Lett ; 10(15): 4177-4184, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31291544

RESUMO

It is challenging to improve the emission efficiency of Mn-doped CsPbCl3 (Mn:CsPbCl3) nanocrystals (NCs) because the excellent optical performances are dependent on high doping efficiency and few defects and traps. Steady-state and time-resolved photoluminescence (PL) spectroscopies were used to investigate the luminescence properties of Mn:CsPbCl3 NCs with different Mn doping levels synthesized in the presence of nickel chloride. The doping efficiency of Mn ions in Mn:CsPbCl3 NCs was greatly enhanced in the presence of NiCl2, and the PL wavelength of Mn2+ ions was tuned from 594 to 638 nm by varying the concentration of dopant Mn from 0.11% to 15.25%. The high emission quantum yields of Mn:CsPbCl3 NCs with orange and red emissions peaked at 600 and 620 nm in hexane were 70% and 39%, respectively. The improvement in doping and emission efficiencies of Mn2+ was attributed to the enhanced formation energies of the Mn doping under the Mn and Ni codoped configuration and the resulting reduction of defects and traps in Mn:CsPbCl3 NCs with incorporation of Ni2+ ions.

14.
BMC Surg ; 19(1): 99, 2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31349822

RESUMO

BACKGROUND: Ankylosing spondylitis (AS) is a chronic inflammatory disease that primarily affects spine and paraspinal soft tissue. Ankylosing spondylitis is one of the causes of osteoporosis and patients with ankylosing spondylitis tend to have spinal fractures due to limited mobility and osteoporosis. In recent years, due to the increase in the number of patients with AS, patients with AS and thoracolumbar spine fractures have gradually increased. In the past 1 year, we have treated 3 cases of AS with thoracolumbar spine fractures via simple posterior internal fixation and this paper aims to report its clinic effect. CASE PRESENTATION: All the three patients selected had a history of ankylosing spondylitis for nearly 30 years, and one of them developed a thoracolumbar spine fracture after falling when he walked, and the other two developed a thoracolumbar spine fracture without any reason. They were hospitalized for "low back pain" and were diagnosed as fractures after careful physical examination and imaging examinations such as X-ray, CT, and MRI. After the preoperative preparation was completed, all the three patients underwent surgery with simple posterior internal fixation-reduction of the fracture and pedicle screw fixation via posterior approach. All the implants-pedicle screws and connecting rods-are made of titanium alloy. For postoperative management, we asked all the patients to stay in bed for 3 weeks after the operation, and then slowly move down with the help of crutches. Fracture healing and neurological function recovery were observed postoperatively. All the three patients recovered satisfactorily after surgery, and the follow-up confirmed that the fracture healed successfully after 3 months. CONCLUSIONS: The 3 patients included 2 men and 1 women. All the 3 patients recovered well after surgery, and the follow-up confirmed that the fracture healed successfully after 3 months. One man developed urination dysfunction after operation and recovered to normal 3 months after rehabilitation exercise.


Assuntos
Fixação Interna de Fraturas/métodos , Vértebras Lombares/lesões , Fraturas da Coluna Vertebral/cirurgia , Espondilite Anquilosante/complicações , Vértebras Torácicas/lesões , Feminino , Humanos , Vértebras Lombares/cirurgia , Masculino , Pessoa de Meia-Idade , Fraturas da Coluna Vertebral/etiologia , Vértebras Torácicas/cirurgia
15.
J Cell Biochem ; 120(8): 14116-14126, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30977239

RESUMO

Ectoparasites repress host immune responses while they obtain nutrition from their hosts. Understanding the immunosuppressive mechanisms between ectoparasites and their hosts will provide new strategies to develop potential immunosuppressive drugs against immune disorder diseases. Previously, we have discovered that a small peptide, immunoregulin HA, from the horsefly (Hybomitra atriperoides) may play an immunosuppressive role in rat splenocytes. However, the targeting cells and detailed mechanisms of immunoregulin HA in immunosuppressive reactions are not well defined. Here, we show that immunoregulin HA reduces the secretion of proinflammatory cytokines upon lipopolysaccharide (LPS) stimulation. Interestingly, we discover that the major cytokines repressed by immunoregulin HA are secreted by macrophages, rather than by T cells. Furthermore, immunoregulin HA inhibits macrophage maturation and phagocytosis. Mechanically, the activations of c-JUN N-terminal kinase and extracellular signal-regulated kinase upon LPS stimulation are decreased by immunoregulin HA. Consistently, immunoregulin HA treatment exhibits an anti-inflammatory activity in a mouse model of adjuvant-induced paw inflammation. Taken together, our data reveal that immunoregulin HA conducts the anti-inflammatory activity by blocking macrophage functions.

16.
AIDS ; 33(9): 1431-1439, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-30889014

RESUMO

OBJECTIVE: The current study aimed to understand epidemiological feature and critical factors associated with pathogenesis of circulating recombinant form (CRF) 01_AE strains in Northeast China. DESIGN: Compared analysis was made between CRF01_AE and non-CRF01_AE samples to understand the pathogenicity features of CRF01_AE. Further analyses between CRF01_AE samples with high or low CD4 cell counts and between samples with different coreceptor usages were done to explore the possible factors correlating to the pathogenesis of CRF01_AE viruses. METHODS: The genotypes of newly identified strains were determined by phylogenetic analyses using Mega 6.06. Coreceptor usage was predicted by Geno2Pheno algorithm. Potential N-linked glycosylation site (PNGS) number was calculated using the online N-glycosite software. The properties of amino acid sequences were analyzed by the online ProtParam tool. RESULTS: CRF01_AE become the main HIV-1 genotype since 2010. Compared with non-CRF01_AE group, the CRF01_AE group showed a higher proportion of samples with CD4 cell count less than 200 cells/µl. Shorter amino acid length, fewer PNGSs and the presence of a basic motif R/KNXT or NR/KT in V4 correlated to a lower CD4 cell count, and existence or coexistence of Thr12, Arg13, Val21 and Lys33, presence of more than 4 of net charges and lack of the PNGS within V3 favored to the X4/R5X4 coreceptor usage of CRF01_AE viruses. CONCLUSION: CRF01_AE has dominated HIV-1 genotype in Northeast China. Infection with CRF01_AE exhibited a fast disease progression, which may be associated with specific amino acid residues and PNGSs in V3 and V4 regions as well as amino acid length of V4 region.

17.
Am J Transl Res ; 11(2): 1040-1048, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30899403

RESUMO

BACKGROUND: The teaching of endoscopic endonasal surgery has always been difficult because of the complex structure of the nasal cavity, and the unique endoscopic view angle and endoscopic surgical tools. In this study, we have designed a 3D printed multi-color model for training of endoscopic endonasal surgery, and obtained preliminary application results. METHODS: The 3D printed model contained facial skin, bony skeleton, internal carotid artery, turbinate, optic chiasm, and a special sellar base with appropriate colors. After it was printed, six otolaryngologists and neurosurgeons assessed the model. Twenty graduate students and residents from otolaryngology or neurosurgery, without prior experience in endoscopic endonasal surgery were recruited and consented for the training. The training results were recorded. The subjective feeling of participants in terms of using 3D printed model in surgical training was investigated after training. RESULTS: All experts strongly agreed or agreed that the 3D printed model has realistic anatomical structure of nasal passage and appropriate colors for different parts, and is a good teaching tool. As the trainees practiced more, the rate and quality of endoscopic operation increased gradually. Compared to the first practice, all recorded training parameters were improved significantly (all P < 0.05). All participants strongly agreed or agreed that they benefited from the training and the 3D printed model can inspire interest and enthusiasm of endoscopic endonasal surgical training. CONCLUSION: This 3D printed model has realistic anatomical structure of nasal passage and appropriate colors for different parts, and could be a good teaching tool of endoscopic endonasal surgery.

18.
ACS Nano ; 13(2): 1635-1644, 2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-30812095

RESUMO

Edges of two-dimensional (2D) halide perovskites are found to exhibit unusual properties such as enhanced photoluminescence lifetime and reduced photoluminescence emission energy. Here, we report the formation mechanism and the dynamic nature of edge states on exfoliated 2D halide perovskite thin crystals. In contrast to other 2D materials, the edge states in 2D perovskites are extrinsic and can be triggered by moisture with a concentration as low as ∼0.5 ppm. High-resolution atomic force microscopy and transmission electron microscopy characterizations reveal the width of the low-energy states is ∼40 nm wide. A temperature-dependent photoluminescence study suggests the edge states are a combination of several lower-energy states. Importantly, we demonstrate that the charge carriers on the dynamically formed edge states are not only long-lived but also highly mobile and can be conducted along the edges effectively with high mobilities of 5.4-7.0 cm2 V-1 s-1. This work provides significant insights on the origin of the edge states in 2D perovskites and provides routes to manipulate their optical and electrical properties through controlling their edges.

19.
Annu Rev Phys Chem ; 70: 219-244, 2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-30883273

RESUMO

We highlight the recent progress in ultrafast dynamic microscopy that combines ultrafast optical spectroscopy with microscopy approaches, focusing on the application transient absorption microscopy (TAM) to directly image energy and charge transport in solar energy harvesting and conversion systems. We discuss the principles, instrumentation, and resolutions of TAM. The simultaneous spatial, temporal, and excited-state-specific resolutions of TAM unraveled exciton and charge transport mechanisms that were previously obscured in conventional ultrafast spectroscopy measurements for systems such as organic solar cells, hybrid perovskite thin films, and molecular aggregates. We also discuss future directions to improve resolutions and to develop other ultrafast imaging contrasts beyond transient absorption.

20.
Inorg Chem ; 58(4): 2315-2329, 2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30706716

RESUMO

Crystallization of perovskite structure chromites (ACrO3) in aqueous conditions is difficult owing to the amphoteric nature of the Cr3+ in the alkaline-mediated reaction conditions. This is especially true for the small metal cations at the A-site with large distortion angle of CrO6 octahedral and small Goldschmidt tolerance factors. Here, we performed a progressive dehydration crystallization strategy to synthesize four RECrO3 with the smallest radii of rare earth elements (Er, Tm, Yb, Lu) in mild hydrothermal conditions. Profile refinement of the high-resolution powder X-ray diffraction results indicated slightly longer unit cell parameters of  a and c in our samples with a higher distorted angle of CrO6 octahedral units along ⟨010⟩ direction. All of the samples show rounded rectangle plate morphology with uniform distribution of particle sizes. These four RECrO3 crystals can only form in a very narrow mineralization temperature range, i.e., 260-280 °C and 4.45-6.24 M of KOH. HRTEM results indicated that the normal crystallographic direction is ⟨001⟩, and the lattice of steps at the edge of elliptic rounded crystal is consistent with the bulk, which demonstrated single crystalline nature of the as-obtained crystals. Room-temperature Raman and FT-IR spectra reveal a continuous symmetry mode shift-dependent on the radii of A-site rare-earth cations. Temperature-dependent magnetization curves of RECrO3 show typical antiferromagnetism to paramagnetism transition with Néel temperature of 93, 90, 86, and 83 K for ErCrO3, TmCrO3, YbCrO3, and LuCrO3, respectively. Samples of YbCrO3 and LuCrO3 show clear magnetization reversal and exchange bias phenomena below their Néel points. This paper indicates that the coupling of magnetic exchange in perovskite structure oxides could be tailorable in mild hydrothermal condition, towards the exploration of new magnetic and other physical properties.

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