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91.
In this article, tissue layers and cells characteristics of the Brazil nut (Bertholletia excelsa H.B.K.) shell (tegument), brown skin (testae), and edible part (cotyledons) were identified by stereoscopy (SM) and scanning electron microscopies (SEM). (a) The shell (a lignin rich, protective wall) varies in thickness throughout the nut structure and comprises different tissue types (total 3)/texture (hard/mid‐hard/soft), layers (2 to 5), colors (light to dark brown and white to cream), cell shape (amorphous/flattened on both surfaces; polygonal and cylindrical with thick, porous primary and secondary wall in cross‐section), and vascular distribution (helically and polyedrical thickened vessels at soft tissue and locule/channel structures). These variations are observed either in the shell faces, face corners, nut tips, or locule in testae. (b) The brown skin (shell nut part linked to both the shell and edible part) is made of flattened irregular‐shaped parenchymal cells distributed in several layers with more flexible fibrous, thinner wall tissue than shell. It has both rough and smooth shiny texture on the upper and lower surfaces, respectively. However, the nut (c) edible part, that is the nut storage tissue, shows several different tissue/cell layers starting from epidermis (double/triple cells sequence of round and palisade shapes) layer–the endosperm tissue. The parenchymal tissues show cells of irregular shape with small and larger sizes distributed in regular and randomly layers, respectively, separated by a short meristem tissue layer. The cortex cells increase in size as they approach the cotyledons junction. The Brazil nut part's tissue layers and cells were identified by the SM and SEM microscopy methods applied, which provides knowledge for further understanding of nut alterations that may occur either in the forest or during the factory processing.  相似文献   
92.
目前大部分试井数学模型将表皮系数视为常数,然而这仅是一种简化的处理。在实际生产过程中,注入或产出的流体可能冲刷岩石颗粒或者携带杂质颗粒进入地层,因此表皮系数是随时间变化的。文中将受影响区域的平均渗透率定义为一个时间的函数,利用经典表皮系数的定义,建立了表皮系数与时间的关系式,称之为变表皮系数;将该变表皮系数代替传统试井解释模型内视为常数的表皮系数,建立变表皮系数试井解释数学模型;利用拉普拉斯变换求解出该模型在拉氏空间内的解,并利用Stehfest数值反演计算出实空间的解;做出无量纲井壁压力和压力导数随时间变化的双对数图,并分析了变表皮系数表达式中各参数对无量纲井壁压力及压力导数的影响。文中利用胜利油田胜2区块一口井的实测试井数据进行实例分析,说明了该模型的适用性。  相似文献   
93.
Consumer behavior is complicated. In the cosmetic market, personal intuition and fashion trends for color selection are guidelines for consumers. A systematic method for female facial skin‐color classification and an application in the makeup market are proposed in this study. In this article, face recognition with a large number of images is first discussed. Then, an innovative method to capture color at selected points is presented and complexion‐aggregated analysis is performed. This innovative method is an extension of face‐recognition theory. Images in RGB format are converted to CIELAB format during data collection and then Fuzzy C‐means theory is used to cluster and group the data. The results are classified and grouped in Lab value and RGB index. Two programs are created. The first program, “FaceRGB,” captures color automatically from images. The second program, “ColorFCM,” clusters and groups the skin‐color information. The results can be used to assist an expert system in the selection of customized colors during makeup and new‐product development.  相似文献   
94.
The wearable intelligent electronic product similar to electronic skin has a great application prospect. However, flexible electronic with high performance pressure sensing functions are still facing great challenges. In this paper, the highly sensitive flexible electronic skin (FES) based on the PVDF/rGO/BaTiO3 composite thin film was fabricated using the near-field electrohydrodynamic direct-writing (NFEDW) method. The PVDF/rGO/BaTiO3 composite solution was directly written on flexible substrate by the NFEDW method to fabricate FES with micro/nano fiber structure, which has the function of sensing pressure with high sensitivity and fast response. The surface morphology and microstructure were characterized by SEM, AFM, and optical microscope in detail. The fabricated FES has high sensitivity (59 kPa−1) and faster response time (130 ms). FES has been successfully applied to the detection of human motion and subtle physiological signals. The experimental results show that FES has good stability and reliability. FES can recognize human motion, and it has a broad application prospect in the field of wearable devices.  相似文献   
95.
Objective: The aim of this study was to evaluate and compare the permeation of model drug indomethacin (IND) from various types of gels through several semipermeable membranes.

Methods: Permeation of IND from gels based on carbomer (CA), hydroxyethylcellulose (HEC), and polyacrylamid/laureth-7/isoparaffin was performed via diffusion cell method through membranes: shed snake skin, full thickness chicken skin, mucosa of pork small intestine, and cellophane.

Results: The least permeation of IND was observed in the case of shed snake skin and full thickness chicken skin. It did not exceed 5.4% of original amount in the preparation after 3?h of measurement regardless the type of gel. In the case of mucosa of pork small intestine and cellophane the permeated amount of IND ranged from 9.4 to 55.4% depending on the type of gelling agent used. There was also quite a significant influence of a gelling agent on the permeation of IND observed. The permeation of IND was highest from CA gel, where it ranged from 0.6 to 52.2% of original amount in the preparation depending on the type of membrane used. Gelling agent inhibiting the permeation the most was HEC, where the permeated amount of IND did not exceed 12.3% regardless the type of membrane used.

Conclusions: In general the permeated amount of IND through biological membranes containing stratum corneum represented just a small part of the amount in original preparation. Gelling agent has significant effect on the extent and rate of permeation.  相似文献   
96.
矿冶粉尘给一线工人皮肤健康带来严重威胁。通过添加微生物灭活芽孢于清洁皂中,研究了不同芽孢添加量对清洁皂去污能力的影响,对比了硅藻土、活性炭和芽孢添加皂在粉尘去污和重金属去除方面的异同,并通过感官评价测试了三种皂在皮肤清洁方面的效果。结果表明,添加硅藻土可以达到80%的粉尘去除率。而活性炭尽管比表面积高,但微粒细小同样易于吸附于手掌纹理中,造成二次污染,故去除率最低。在基础皂中添加1%(w/w)灭活芽孢对粉尘污染的去污率达到了95%,二次洗涤可将重金属去除率从90%提高到95%以上。感官评价中,黑色活性炭的吸附作用造成了清洗后的手掌依然不够干净,观感最差;硅藻土皂的清洁效果接近日常家用皂,观感居中;而芽孢皂的清洁效果最明显,观感最佳。  相似文献   
97.
Several occupational groups are exposed to periods of low ambient temperatures while performing manual work tasks outdoors. Work tasks typically include heavy lifting, tool handling, and overhead work. This study evaluated the effect of working position and cold environment on muscle activation level (%RMSmax) and fatigue in the upper limb during manual work tasks. Fourteen male participants (25 ± 3 years, 80.9 ± 6.4 kg, 182 ± 5 cm) completed a 2-h test protocol consisting of five test periods alternating with four work periods, wearing identical sets of clothing, under cold (−15 °C) and control (5 °C) conditions. The work periods consisted of manual work at the hip level, manual overhead work, and a lifting exercise. The test periods consisted of isometric maximal voluntary contractions (MVC) and seated rest. Skin temperatures decreased during cold exposure, especially in the extremities. %RMSmax in the forearm was higher in the cold condition both during overhead work and work at the hip level than that for the same work in the control condition, especially at the end of the test when the difference was approximately 25% (equating to 2–3 %RMSmax). For the middle deltoid muscle, the %RMSmax was approximately three times (or 10 %RMSmax) higher during overhead work than work at the hip level, but there was no additional cost of working in the cold. Signs of deltoid muscle fatigue (decrease in electromyography median power frequency and an increase in %RMSmax) were observed during the overhead work periods in both temperature conditions. No decrease in MVC, as a sign of overall muscle fatigue, was observed in either condition.Relevance to industryThis study demonstrated that when wearing suitable cold-weather protective clothing, the adverse effect of work posture is much higher than that of cold on muscle demand and physical strain.  相似文献   
98.
目的研究花生红衣中提纯的原花青素(peanut skin procyanidins,PSPs-1)在化学模拟体系和食品体系中对丙烯酰胺产生的抑制效果,并对PSPs-1的组成成分进行鉴定。方法以天冬酰胺和葡萄糖反应产生丙烯酰胺作为化学模拟体系,以油炸薯条生成丙烯酰胺作为食品体系,通过HPLC分析PSPs-1对2种体系中丙烯酰胺的抑制效果,并采用反相高效液相色谱-电喷雾-质谱联用(RP-HPLC-ESI-MS/MS)技术对PSPs-1进行鉴定。结果在化学模拟体系中,PSPs-1具有明显的抑制丙烯酰胺生成的效果,并显示出非线性浓度效应,在添加量为0.1 mg/m L时达到最大抑制率,为(51.22?3.15)%;在食品体系中,PSPs-1的浓度及浸渍薯条时间皆对丙烯酰胺的产生有明显抑制效果,并显示一定的量效关系,PSPs-1浓度为0.1 mg/m L达到最大抑制率,为(51.03?2.97)%,且当浸渍时间为90 s时抑制效果最好(50.79±1.86)%。PSPs-1经RP-HPLC-ESI-MS/MS分析和与对照品比较,其可能是由含有儿茶素和表儿茶素的黄烷醇多酚组成。结论由儿茶素和表儿茶素组成的PSPs-1在2种体系中具有明显抑制丙烯酰胺产生的效果。  相似文献   
99.
Management of dairy cow productivity requires monitoring of their nutritional status by visual observation. It has been suggested that changes in hair coat appearance are among the indicators of nutritional state in dairy cows. Temporal changes in the skin morphology in cows, however, have not been reported. In this study, we examined the changes in the skin of dairy cows that occur during the peripartum period. Seven pluriparous cows were used. Skin samples were collected at 28 d before the due date and 28 d and 56 d after calving for morphological examination. Hair follicle width was 108.8 ± 5.9 µm (±SD) in the dry period, 95.5 ± 5.5 µm at 28 d after calving, and 104.2 ± 5.3 µm at 56 d postpartum. The percentages of anagen hair follicles during these 3 periods were 41.4 ± 3.4, 18.5 ± 3.4, and 32.3 ± 3.3%, respectively. The corresponding sebaceous gland sizes were 8,362.0 ± 707.6, 7,800.0 ± 831.4, and 9,186.8 ± 962.6 µm2, respectively. Hair follicle width was positively correlated with percentage of anagen hair follicles. The thickness of epidermal and proliferation rate of epidermal cell were also correlated. However, the hair follicle width, sebaceous gland size and cell proliferation rate, and thickness and proliferation rate of epidermal cells did not show any marked changes.  相似文献   
100.
In this article, we present an evaluation method for the skin color distribution in the face area. Unlike previous methods that extract a specific area, our method subdivides the entire face into small regions and analyzes detailed, per-frame textures. Our evaluation method for skin color distribution is based on facial feature points and includes segmentation that takes into account the facial skeleton and muscle orientation. The use of facial feature points enables a comparison at relatively equal positions on the face without depending on the shape or size of the individual's face. Our evaluation method is versatile, and as an application, we clarified age-specific features and seasonal variations of facial color distribution. As a result of applying this evaluation method to the facial images of women aged 20 to 78 years, we confirmed that the lightness of the face decreased as age increased. In particular, the decrease in lightness was remarkable in the region along the cheekbone, from the temple to the center of the cheek. Furthermore, we analyzed the seasonal changes of melanin distribution in the face area. This showed that the melanin index increased particularly in the cheekbone area in the summer when the influence of ultraviolet rays became large. Our novel methodology and the data presented in this article will be useful in various fields, such as dermatology, cosmetics, and computer vision.  相似文献   
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