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1.
Heliyon ; 8(11): e11641, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36439751

ABSTRACT

The Hmong is one of the oldest ethnic groups in south-western China, and sound plays an important role in their culture. According to the general classification of landscape science, the rural soundscape of Hmong villages is divided into three types: a point soundscape dominated by a single sound source, a line soundscape with a typical Hmong rural village alley space as the sound field interface, and an area soundscape with the Bronze-drum Square, the only open public space of Hmong nationality, as the field. Combined with a sound collection and field test during field investigation, we obtained the characteristics of various rural soundscapes and evaluated the acoustic environment. The results showed that the "point" soundscape of medium- and low-frequency powder shotgun and wooden drum sounds in the unclosed Hmong villages exceed the transmission distance and sound durability. The "line" soundscape utilizes the turning point and envelope of different spaces to increase the acoustic reflection surface and create reverberation, increasing the propagation time and distance of the sound, and emphasizing the directivity of the sound through a long and narrow space. The "surface" soundscape includes the richest medium- and high-frequency-based human voice and music sounds and medium- and low-frequency musical instrument sounds, among others. The values of T30, EDT, and C80 in the sound field, all changed significantly because of the lack of acoustic reflection from the ceiling, through the top opening. Finally, the study reveals the cultural association between rural soundscape and space, which is reflected in the Hmong's "defensive" function and "group" culture. Thus, the Bronze-drum Square sound field does not meet the requirements of the current specification of cultural interpretation, and it is in the participatory Hmong performance mode, centered on drum club group structure.

2.
Materials (Basel) ; 13(21)2020 Oct 29.
Article in English | MEDLINE | ID: mdl-33138293

ABSTRACT

A series of oligomeric (salen)Mn(III) complexes featuring tartrate linkers were prepared and immobilized over layered double hydroxide, and then used as catalysts for asymmetric epoxidation of unfunctionalized olefins. Comprehensive characterizations including 1H NMR, FT-IR, UV-Vis, elemental analysis, GPC, and ICP-AES were used to illustrate structures of oligomeric (salen)Mn(III) complexes, while powdered XRD, nitrogen physisorption, together with XPS studies provided further details to detect structures of heterogeneous catalysts. Interestingly, scanning electron microscopy found an interesting morphology change during modification of layered supporting material. Catalytic experiments indicated that configuration of major epoxide products was determined by salen chirality more than that of tartrate linker, but enantioselectivity (e.e. values) could be enhanced when tartrate and salen showed identical chiral configurations. Furthermore, the (R,R)-salen moieties linked with (R,R)-tartrate spacers usually offered higher enantioselectivity compared to other combinations. Lastly, Zn(II)/Al(III) layered double hydroxide played as a rigid supporting material in catalysis, showing positive chiral induction and high recycling potential in catalytic reactions.

3.
Front Chem ; 8: 532, 2020.
Article in English | MEDLINE | ID: mdl-32793546

ABSTRACT

The aqueous room temperature mono-dehydration of sugar alcohols (D-sorbitol and D-mannitol) was conducted using functionalized yttrium oxide nanocatalysts prepared via sol-gel methods. Materials exhibited high selectivity to mono-dehydration products. Solvent and catalyst effects were also investigated and discussed. The introduction of titanium into the yttrium oxide framework would decrease both substrate conversion and mono-dehydration efficiency. In addition, studies of the catalytic mechanism indicate high mono-dehydration efficiency may come from the stability of the formed intermediate during catalysis. This work provides a highly efficient and benign system for catalytic mono-dehydration of sugar alcohols.

4.
J Environ Manage ; 253: 109722, 2020 Jan 01.
Article in English | MEDLINE | ID: mdl-31666215

ABSTRACT

Improvement of the sound environment is essential for improving the overall quality of the urban environment and for reflecting the characteristics of a city. Unfortunately, some soundscapes in cities are gradually being destroyed by the rapid development. Therefore, it would appear that the preservation of soundscapes is as necessary and crucial as noise control in cities. In this paper two field studies were carried out at two stages to explore the types and characteristics of urban soundscapes that should be preserved, based on the example of Tianjin, China. At stage one, 2504 respondents participated in social surveys to recommend the soundscapes worthy of preservation in the city. At stage two, a group soundscape walk with twenty-three participants was carried out to explore the characteristics of soundscapes worthy of preservation suggested by the respondents at the first stage. The following results were obtained: (1) regarding the attitude towards the urgency of soundscape preservation, 79% of the respondents thought it was urgent or very urgent, with an average score of 4.04 (five-point numeric scale was used and five meant very urgent). (2) The majority of soundscapes worthy of preservation were located in urban parks and historic districts with respective proportions of 66% and 20%. The top three sound source categories of these soundscapes were social/communal sounds (talking, bells, laughter, and sounds from human activities), animal sounds (birdsong and sounds from non-domesticated animals) and water sounds. (3) Relaxation, vibrancy, representativeness, strength, and richness were principal characteristics of the soundscapes worthy of preservation. (4) Based on their characteristics, these soundscapes were classified into five clusters using hierarchical cluster analysis (HCA). They were clusters of relaxing nature soundscape, vibrant nature soundscape, vibrant human activity soundscape, culture-related soundscape and traditional soundscape. The dominant characteristic of each cluster was driven by its sound mark rather than the dominant sound.


Subject(s)
Parks, Recreational , Sound , Animals , Attitude , China , Cities , Humans
5.
Ann Plast Surg ; 78(1): 111-118, 2017 Jan.
Article in English | MEDLINE | ID: mdl-26914352

ABSTRACT

INTRODUCTION: Meta-analyses are considered to be an important source of evidence. This review aims to systematically assess the quality of meta-analyses addressing topics in plastic surgery. METHODS: Electronic databases were selected for systematic review. A search was performed focusing on communication addresses containing terms related to plastic surgery, and detailed inclusion criteria were used. Related data were extracted and recorded according to the items of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. To assess the quality of the meta-analyses over time, studies published before and after PRISMA were evaluated. RESULTS: A total of 116 meta-analyses were included. There was 1 study that was fully in compliance with the PRISMA items. The main flaws impacting the overall quality of the included studies were in the following areas: structured summary (48%), protocol and registration (2%), full electronic search strategy (35%), risk of bias in individual studies (41%), additional analyses (27%), risk of bias within studies (47%), additional analysis (30%), and funding (47%). Study quality was evaluated using relative risks (RR) with a 95% confidence interval (95% CI); this revealed that there were few significant improvements in adherence to the PRISMA statement after its release, especially in selection (RR, 1.80; 95% CI, 1.08-2.99), results of individual studies (RR, 2.88; 95% CI, 1.41-5.91), synthesis of results (RR, 3.08; 95% CI, 1.32-7.17), and funding (RR, 1.65; 95% CI, 1.21-2.24). CONCLUSIONS: There have been measurable improvements in the quality of meta-analyses over recent years. However, several serious deficiencies remain according to the PRISMA statement. Future reviewers should pay more attention to not only reporting the main findings but also encouraging compliance with proper standards.


Subject(s)
Meta-Analysis as Topic , Plastic Surgery Procedures , Research Design/standards , Humans , Research Design/trends
6.
Neuroimage ; 134: 204-212, 2016 07 01.
Article in English | MEDLINE | ID: mdl-27039704

ABSTRACT

There has been a long debate about the neural mechanism of event-related potentials (ERPs). Previously, no evidence or method was apparent to validate the two competing models, the evoked model and the oscillation model. One argument is whether the pre-stimulus brain oscillation could influence the following ERP. This study carried out an innovative visual oddball task experiment to investigate the dynamic process of visual evoked potentials. A period of stable oscillations of specified dominant frequencies and initial phases, i.e. the steady-state baseline, would be induced before responses to transient stimuli of different contrasts, which could overcome the artifact problem caused by the 'sorting' method. The result first revealed a 'three-period-transition' for the generation of visual evoked potentials by an objective decomposition. The ERP almost retained the preceding oscillation during the first period, provided an unstable negative potential in the second period, and generated the N1 component in the third period. The cross term analysis showed that the evoked model couldn't be the whole explanation for the ERP generation. Furthermore, the component analysis revealed that the N1 latency was sensitive to the initial phase under the low stimulus contrast (supporting the oscillation model) but not under the high stimulus contrast (supporting the evoked model). It demonstrated that the external stimulus contrast is a significant factor deciding the explicit model for ERPs. Our method and preliminary results may help reconcile the previous, seemly contradictory findings on the ERP mechanism.


Subject(s)
Biological Clocks/physiology , Brain Waves/physiology , Evoked Potentials, Visual/physiology , Models, Neurological , Visual Cortex/physiology , Visual Perception/physiology , Adult , Computer Simulation , Female , Humans , Male , Photic Stimulation/methods , Reproducibility of Results , Sensitivity and Specificity
8.
Lasers Surg Med ; 48(4): 360-4, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26749479

ABSTRACT

BACKGROUND AND OBJECTIVES: Keloids are fibroproliferative lesions of unknown origin that are characterized by increased collagen deposition. Vascularization may play a role in the pathogenesis of keloids, but existing reports are contradictory. Thus, we assessed perfusion within keloids and surrounding skin using laser speckle contrast imaging (LSCI). STUDY DESIGN/MATERIALS AND METHODS: Twenty-one patients with 61 untreated keloids were enrolled into this study. LSCI was used to evaluate blood flow in the keloids and surrounding skin. Three regions of interest were manually defined: keloids (K), skin adjacent to keloids (A), and nonadjacent skin separated by at least 0.3 cm from the edge of the keloids (N). Mean perfusion in each of these regions was determined and ratios (K/N, A/N) were calculated. RESULTS: Significantly higher perfusion was noted in keloids and adjacent skin compared with nonadjacent skin (P < 0.05). The mean values (95% confidence intervals) of the ratios were: K/N = 2.41 (2.28-2.54) and A/N = 1.33 (1.28-1.37). A heterogeneous perfusion map was frequently observed. Mean perfusion in keloids and nonadjacent skin in the chest region was significantly higher than that on the back (P < 0.05). There was no statistical signficant difference in K/N at different locations (P > 0.05). CONCLUSIONS: Perfusion values in keloids and adjacent skin were significantly higher than those in nonadjacent skin. LSCI may be a suitable and useful way of assessing perfusion in keloids.


Subject(s)
Keloid/physiopathology , Regional Blood Flow , Skin/blood supply , Adolescent , Adult , Aged , Child , Female , Humans , Keloid/diagnostic imaging , Lasers , Male , Middle Aged , Optical Imaging/instrumentation , Optical Imaging/methods , Skin/diagnostic imaging , Young Adult
9.
Chin Med Sci J ; 30(2): 76-9, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26148996

ABSTRACT

OBJECTIVE: To investigate reliability of the infra-nipple broken line incision for breast augmentation. METHODS: From January 2012 to January 2013, 15 patients underwent primary bilateral retromuscular breast augmentation with round textured silicone-gel implants and a novel infra-nipple broken line incision. Preoperatively, a semicircular incision was marked along the inferior base of the nipple. It was then extended bilaterally using two transverse right-angled geometric broken lines within the pigmented areolar skin. Follow-up was performed to evaluate the sensation of nipple-areolar complex, the scar, and the shape and texture of the breasts. RESULTS: The average follow-up was 6.7 months. Most of the patients complained of paresthesia of the nipple or breast skin, but transient decreased sensation improved within 3 months. No patients showed permanent sensory changes of the nipple areolar complex at a minimum follow-up of 4 months. The scars were imperceptible in all patients. CONCLUSION: We believe that for selected patients, the infra-nipple broken line incision is a practical and reliable method to achieve aesthetic result.


Subject(s)
Mammaplasty/methods , Adult , Female , Follow-Up Studies , Humans , Middle Aged
13.
Zhonghua Zheng Xing Wai Ke Za Zhi ; 30(2): 89-92, 2014 Mar.
Article in Chinese | MEDLINE | ID: mdl-24941756

ABSTRACT

OBJECTIVE: To investigate the feasibility of immediate breast and nipple-areola reconstruction after skin-sparing mastectomy. METHODS: 24 patients who received skin-sparing mastectomy underwent immediate breast reconstruction with or without breast implants. The nipple-areola complex is also reconstructed with the skin paddle of the latissimus dorsi flap in one stage. RESULTS: All the latissimus dorsi myocutaneous flaps survived completely. Partial necrosis happened in two reconstructed nipples which healed after dress changing. The follow-up period ranged from 6 to 12 months. 3 patients presented with capsular contracture (Baker I), with no necessary of surgical revision. The retraction rate of reconstructed nipples projection is 35.4% at 6 months postoperatively and 38.6% at 12 months postoperatively. 91.7% of patients were satisfied or very satisfied with the breast shape, while 83.3% were satisfied or very satisfied with the breast volume. All the patients considered the reconstructed nipple very good, while 91.6% were satisfied with the nipple projection. 91.7% considered immediate nipple reconstruction to be very important, and 8.3% considered it to be important. 66.7% considered the new breast could replace the breast they had lost, and 8.3% considered that it could not. CONCLUSION: For skin-sparing mastectomy, immediate breast and nipple reconstruction can achieve good aesthetic results.


Subject(s)
Mammaplasty/methods , Myocutaneous Flap/transplantation , Nipples/surgery , Superficial Back Muscles/transplantation , Breast Neoplasms/surgery , Esthetics , Female , Humans , Mammaplasty/psychology
15.
Biomed Mater Eng ; 24(1): 349-55, 2014.
Article in English | MEDLINE | ID: mdl-24211916

ABSTRACT

Varieties of neurophysiological measures have been utilized in visual attention studies. The linear parameters like power spectrum are the most commonly used features in the existing studies. In this paper, however, nonlinear parameters including approximate entropy, sample entropy and multiscale entropy were tested. All subjects were instructed to perform tasks with three different attention levels (i.e. attention, no attention and rest) in two experiments. Nonlinear features were extracted from the EEG signals. Then, statistical analyses and classification with support vector machine (SVM) were performed. A comparison between the classification results based on the linear feature / and the sample entropy was performed for further analysis. The results suggest that sample entropy stands out in the dynamical parameters with the accuracies of 76.19% and 85.24% in recognition of three levels of attention for the two experiments respectively. And the further comparison shows that the sample entropy performs even better than the / power ratio. It is suggested that nonlinear dynamical parameters may be indispensable for a robust attention recognition system.


Subject(s)
Attention , Electroencephalography , Pattern Recognition, Automated , Vision, Ocular , Adult , Algorithms , Artifacts , Computer Simulation , Entropy , Healthy Volunteers , Humans , Linear Models , Nonlinear Dynamics , Normal Distribution , Reproducibility of Results , Signal Processing, Computer-Assisted , Stochastic Processes , Support Vector Machine , Young Adult
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