皮肤学基础知识

皮肤学基础知识 皮肤学基础知识 皮肤的功能 保护 知觉 新陈代谢 分泌 排泄 吸收 调节体温 皮肤的 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 面 皮肤的表面是凹凸不平的 皮肤的表面 有点象连绵起伏的山丘，所以隆起的部位我们形象地称之为皮丘。 皮 丘的最高点是汗孔,汗孔下面连着汗腺,汗腺分泌的汗水经由汗孔排 出体外 山丘与山丘之间我们称之为山沟，所以皮丘与皮丘之间也形 象的称之为皮沟。 皮沟的最低处是毛孔,毛孔下面连着毛囊,毛囊旁 边有个袋状的物质皮脂腺,皮脂腺分泌的油脂经由毛孔排出滋润皮 肤。 皮肤的结构 1.皮下组织 2.真皮 3.表皮 表皮层 1 角质层 由扁平无核的死细胞构成 2 透 明层 明显存在于手掌和脚掌 3 颗粒层 由1―3层扁平的或 菱形细胞构成 4 有棘层 为4―8层立方形或多角形细胞，愈向 上逐渐扁平 5 基底层 也称为基底母细胞层;它是表皮的最 底层 皮肤细胞平面图 表 皮 角质层:保护作用，防水，防菌作用。 角质细胞呈片状排列重叠，提供皮肤抵御阳光紫外线、冷热以及环境 等外在刺激，会随着新陈代谢周期 约28天左右 而自然剥落，代谢 周期会因年龄的增长、阳光的曝晒及空气的污染而延长，当老死细胞 没有正常代谢、脱落，皮肤就会产生粗糙、肤色暗沉的现象 透明层:控制皮肤水分、防止水分流失。 颗粒层:防止异物侵入，过滤紫外线。 有棘层:具细胞分裂增殖能力。 基底层:产生新细胞，逐渐往上推，直至形成角质，也就是皮肤的新 陈代谢的过程。含黑色素的多少及聚集状态决定肌肤颜色。 circuit board by hand or tool, the operator shall take anti-static measures. 5.1.3.2.6 site the installation site should be installed in the enclosure with light, dry places, installation should be normal, smooth, firm, perpendicularity tolerance for 3mm/5M, horizontal gradient tolerance for 4mm/5M. 5.1.4 instrument cable tray and junction box install 5.1.4.1 cable channel should be according to the construction plan, Hsien Chu Rami. Construction should be carefully checked before the process piping and equipment layout, and check the cable trough the practical direction, ensure that the cable channel's direction and elevation do not conflict with the process piping and equipment, construction workers correctly. 5.1.4.2 slot must have the support, fixed support spacing should be 2 m, bends must have support bracket cannot be directly welded to a place with thermal expansion. 5.1.4.3 trunking interface connectors and bolts, and set appropriate expansion gap, all online slot bolt head should be inside. 5.1.4.4 slot into the control room should be fireproof and waterproof measures, online slots filled fire outside sealing mastic to prevent flammable gas into the control room. 5.1.4.5 slot when holes are needed, machining, electric and gas welding process shall not be used, open hole, the edges should be sanded smooth and touch up in a timely manner. 5.1.4.6 line after installing reliable earthing, grounding wire connected to the slot spacing shall not exceed 30m. 5.1.4.7 install junction box (1) should be installed in a light, dry place, the ambient temperature should not be more than 450C, box Center height from the ground to about 1100mm; (2) there should be good sealing practices, and identify number; (3) shall not affect the operation, maintenance and access, online slots should be installed on each side. 5.1.5 cable protection pipe preparation 5.1.5.1 instrument cable protection pipe should avoid high 基底层的细胞以圆型长柱状整齐排列，细胞中会夹杂黑色素 麦拉宁色素 ，当受到阳光紫外线的刺激时，为了保护下面的真皮层组织不受伤害，基底层细胞就会开始分泌黑色素来抵御，通常透过周期28天的新陈代谢，黑色素会随细胞形成角质脱落。 表皮健康度 不健康的表皮表现为:干燥、粗糙、干细纹、肤色暗沉、光泽度差、极易过敏 当你的肌肤出现缺水、细纹、肤色暗沉，可以通过及时的补救 措施 《全国民用建筑工程设计技术措施》规划•建筑•景观全国民用建筑工程设计技术措施》规划•建筑•景观软件质量保证措施下载工地伤害及预防措施下载关于贯彻落实的具体措施 来改善肌肤光泽度、细滑度、保水度。正确的护肤品以及美容护理匀可在短时间内让表皮得到修复与改善，且不受年纪所限，即使是七十高龄仍然可以拥有细滑肌肤。 真 皮 由胶原纤维及弹性纤维所构成，是与肌肤老化有直接关系的重要部位。 真皮层还有以下主要附属器官: 汗腺:调节体温、排泄废物。 皮脂腺:分泌油脂，滋润皮肤。 血管:供给皮肤养分和氧气。 真皮层主要功能就是支撑表皮层，维持皮肤良好触感。健康正常的肤质，拥有具弹性、韧性的弹力纤维与饱满的的胶原蛋白组织，让肌肤外观呈现紧实、明亮～老化的皮肤缺少弹性、产生纹路，就是因为真皮组织中的胶原蛋白流失、弹力纤维萎缩所导致 真皮的健康度 一、真皮的健康指标为:紧实度、毛孔粗大程度、有无真性皱纹 circuit board by hand or tool, the operator shall take anti-static measures. 5.1.3.2.6 site the installation site should be installed in the enclosure with light, dry places, installation should be normal, smooth, firm, perpendicularity tolerance for 3mm/5M, horizontal gradient tolerance for 4mm/5M. 5.1.4 instrument cable tray and junction box install 5.1.4.1 cable channel should be according to the construction plan, Hsien Chu Rami. Construction should be carefully checked before the process piping and equipment layout, and check the cable trough the practical direction, ensure that the cable channel's direction and elevation do not conflict with the process piping and equipment, construction workers correctly. 5.1.4.2 slot must have the support, fixed support spacing should be 2 m, bends must have support bracket cannot be directly welded to a place with thermal expansion. 5.1.4.3 trunking interface connectors and bolts, and set appropriate expansion gap, all online slot bolt head should be inside. 5.1.4.4 slot into the control room should be fireproof and waterproof measures, online slots filled fire outside sealing mastic to prevent flammable gas into the control room. 5.1.4.5 slot when holes are needed, machining, electric and gas welding process shall not be used, open hole, the edges should be sanded smooth and touch up in a timely manner. 5.1.4.6 line after installing reliable earthing, grounding wire connected to the slot spacing shall not exceed 30m. 5.1.4.7 install junction box (1) should be installed in a light, dry place, the ambient temperature should not be more than 450C, box Center height from the ground to about 1100mm; (2) there should be good sealing practices, and identify number; (3) shall not affect the operation, maintenance and access, online slots should be installed on each side. 5.1.5 cable protection pipe preparation 5.1.5.1 instrument cable protection pipe should avoid high 二、老化真皮表现为:皮肤明显松驰、毛孔粗大无黑头(尤其是额头处说明已明显老化)、法令纹(三角区鼻翼两侧延伸向嘴角的两条对称纹路)川字纹、眼部皱纹突出加深，已经形成真性皱纹。 真皮的衰老一旦形成，任你再用多贵的化妆品美容护理也不能回复年轻。我们要防患于未然，提早对真皮层进行护养，即可有效的抵抗衰老，留住青春。当然，如果已经开始衰老了，能够做好工作，也能大大延缓老化所造成的破坏。 真皮层保养 心得 信息技术培训心得 下载关于七一讲话心得体会关于国企改革心得体会关于使用希沃白板的心得体会国培计划培训心得体会 无需要用昂贵的护肤品及美容护理，我一样能留住青春～ 我的真皮层的保养心得 防晒 原因:真皮层最大的敌人即是紫外线。它能穿透表皮，直达真皮层，对胶原和弹性纤维产生严重破坏，令它们变性直至断裂，进而产生真性皱纹。 护理:开始得越早越好，不管你是什么年纪。全年防晒。随时随地。无论刮风下雨出太阳，只要是白天就会有紫外线。通常冬天我也会擦防晒霜，夏天更是防晒霜加帽子或遮阳伞。室内也要注意避免让脸部直接暴露在强光中。某些灯，如果日光灯，迪吧舞厅里的黑光灯，都含有紫外线，也应尽量避免。 circuit board by hand or tool, the operator shall take anti-static measures. 5.1.3.2.6 site the installation site should be installed in the enclosure with light, dry places, installation should be normal, smooth, firm, perpendicularity tolerance for 3mm/5M, horizontal gradient tolerance for 4mm/5M. 5.1.4 instrument cable tray and junction box install 5.1.4.1 cable channel should be according to the construction plan, Hsien Chu Rami. Construction should be carefully checked before the process piping and equipment layout, and check the cable trough the practical direction, ensure that the cable channel's direction and elevation do not conflict with the process piping and equipment, construction workers correctly. 5.1.4.2 slot must have the support, fixed support spacing should be 2 m, bends must have support bracket cannot be directly welded to a place with thermal expansion. 5.1.4.3 trunking interface connectors and bolts, and set appropriate expansion gap, all online slot bolt head should be inside. 5.1.4.4 slot into the control room should be fireproof and waterproof measures, online slots filled fire outside sealing mastic to prevent flammable gas into the control room. 5.1.4.5 slot when holes are needed, machining, electric and gas welding process shall not be used, open hole, the edges should be sanded smooth and touch up in a timely manner. 5.1.4.6 line after installing reliable earthing, grounding wire connected to the slot spacing shall not exceed 30m. 5.1.4.7 install junction box (1) should be installed in a light, dry place, the ambient temperature should not be more than 450C, box Center height from the ground to about 1100mm; (2) there should be good sealing practices, and identify number; (3) shall not affect the operation, maintenance and access, online slots should be installed on each side. 5.1.5 cable protection pipe preparation 5.1.5.1 instrument cable protection pipe should avoid high 心得:总之一句话，你要随时记住，紫外线是你青春肌肤最大的敌人，要视它如猛虎野兽。想不让它任意肆虐我们的肌肤，那就要勤于防晒。 补充胶原蛋白 原因:真皮层里的胶原纤维即是来源于胶原蛋白。但它会随时着年龄的增长而不断的流失，人体不能自身合成，必须通过外界的补充，通常流失从25岁开始。那么为肌肤被充胶原蛋白就显得尤为重要。 护理:一是外擦。为了结省银子，使用DIY的左旋C原粉加胶原原粉，自己动手制作精华液。左旋C是促进胶原蛋白的生成所必需的，而现在市面上含左旋C的成品可谓超级昂贵，小妹实在用不起。但DIY的左旋精华液却真是又便宜又好用，再加上左旋不宜保存和浓度的要求，其实发现使用左旋C最好的办法就是DIY。要注意的是左旋和胶原均为大分子，普通的不能渗透至真皮层，所以纳米级的效果最佳。 皮下组织 含大量脂肪细胞，缓冲外来的刺激，皮下脂肪越多，皮肤会较圆润不易碰伤，随着年龄增长，皮下脂肪减少，皮肤会失去弹性，变得松驰。 皮肤的种类 ――干性肌肤 干性皮肤: 特征:毛孔细小、极易形成表情纹、50岁以上的女性及居住在炎热或寒冷气候中的人比较容易有干性皮肤。 问 题 快递公司问题件快递公司问题件货款处理关于圆的周长面积重点题型关于解方程组的题及答案关于南海问题 :女性若不保护她们的皮肤免受外界因素的侵害，则极可能会发circuit board by hand or tool, the operator shall take anti-static measures. 5.1.3.2.6 site the installation site should be installed in the enclosure with light, dry places, installation should be normal, smooth, firm, perpendicularity tolerance for 3mm/5M, horizontal gradient tolerance for 4mm/5M. 5.1.4 instrument cable tray and junction box install 5.1.4.1 cable channel should be according to the construction plan, Hsien Chu Rami. Construction should be carefully checked before the process piping and equipment layout, and check the cable trough the practical direction, ensure that the cable channel's direction and elevation do not conflict with the process piping and equipment, construction workers correctly. 5.1.4.2 slot must have the support, fixed support spacing should be 2 m, bends must have support bracket cannot be directly welded to a place with thermal expansion. 5.1.4.3 trunking interface connectors and bolts, and set appropriate expansion gap, all online slot bolt head should be inside. 5.1.4.4 slot into the control room should be fireproof and waterproof measures, online slots filled fire outside sealing mastic to prevent flammable gas into the control room. 5.1.4.5 slot when holes are needed, machining, electric and gas welding process shall not be used, open hole, the edges should be sanded smooth and touch up in a timely manner. 5.1.4.6 line after installing reliable earthing, grounding wire connected to the slot spacing shall not exceed 30m. 5.1.4.7 install junction box (1) should be installed in a light, dry place, the ambient temperature should not be more than 450C, box Center height from the ground to about 1100mm; (2) there should be good sealing practices, and identify number; (3) shall not affect the operation, maintenance and access, online slots should be installed on each side. 5.1.5 cable protection pipe preparation 5.1.5.1 instrument cable protection pipe should avoid high 展为干性皮肤，使皮肤产生紧绷感，缺乏滋润，干燥、粗糙、脱皮、龟裂，易产生皱纹。 优点:细白 护理重点:防晒、防风 中性皮肤 特性:看起来很健康且质地光滑，很少有痘子及阻塞的毛孔。 问题:夏季时T型部位略为油腻，冬季时偏干，随着年龄的增长，会转变为干性皮肤。 混合性皮肤 特征:T型区有些油腻，而两颊及脸部的外缘有一些干燥。 问题:此类皮肤T型区最易产生粉刺、暗疮，如加以适当的保养，可以使皱纹迟至较晚才出现 油性皮肤 特征:毛孔粗大，较易阻塞，且容易长痘子及其它皮肤瑕疵。 问题:易生黑头、粉刺、暗疮 敏感性皮肤: 特征:易受环境因素及局部涂敷品所刺激，皮肤较薄，可见微细血管。 问题:受外界刺激易出现痕痒、发炎和斑疹。 特征: 红、肿、烫、痒、红斑疹 成因: 皮肤敏感:天生的敏感性肤质、滥用化妆品导致的皮肤敏感 过敏源:花粉、药物、食物、真菌、化妆品、昆虫、粉尘、温度以及其它如:金属饰品有机溶液等都是致敏因素。 过敏反应，是人类与疾病作斗争的一种机体免疫反应，不必惊恐、慌乱。 发展下去的后果: 过敏性问题: circuit board by hand or tool, the operator shall take anti-static measures. 5.1.3.2.6 site the installation site should be installed in the enclosure with light, dry places, installation should be normal, smooth, firm, perpendicularity tolerance for 3mm/5M, horizontal gradient tolerance for 4mm/5M. 5.1.4 instrument cable tray and junction box install 5.1.4.1 cable channel should be according to the construction plan, Hsien Chu Rami. Construction should be carefully checked before the process piping and equipment layout, and check the cable trough the practical direction, ensure that the cable channel's direction and elevation do not conflict with the process piping and equipment, construction workers correctly. 5.1.4.2 slot must have the support, fixed support spacing should be 2 m, bends must have support bracket cannot be directly welded to a place with thermal expansion. 5.1.4.3 trunking interface connectors and bolts, and set appropriate expansion gap, all online slot bolt head should be inside. 5.1.4.4 slot into the control room should be fireproof and waterproof measures, online slots filled fire outside sealing mastic to prevent flammable gas into the control room. 5.1.4.5 slot when holes are needed, machining, electric and gas welding process shall not be used, open hole, the edges should be sanded smooth and touch up in a timely manner. 5.1.4.6 line after installing reliable earthing, grounding wire connected to the slot spacing shall not exceed 30m. 5.1.4.7 install junction box (1) should be installed in a light, dry place, the ambient temperature should not be more than 450C, box Center height from the ground to about 1100mm; (2) there should be good sealing practices, and identify number; (3) shall not affect the operation, maintenance and access, online slots should be installed on each side. 5.1.5 cable protection pipe preparation 5.1.5.1 instrument cable protection pipe should avoid high 迄今为止，科学上仍然不能完全解释为什么不同的人会对不同的物品过敏，部分原因是遗传，部分来源于不同药物间的交叉反应;大部分时候，过敏反应是由于人体内被某种不明原因激活了过于敏感的免疫系统。在皮肤炎症时，就会导致过敏反应的发生率大大增加。 所以:不能简单认为引发过敏的原因就是使用过的产品质量不合格，或者配方不完善引起的，绝大多数情况下是由每个人与人俱来的个体异性所造成了。 发生过敏是我们机体免疫力差，对外界过于敏感。发展下去我们的皮肤抵抗力更差，根本没有办法改善我们的皮肤，使其变得柔滑、细腻、富有弹性、光泽没有皱纹。 解决办法: 如果我们能确定皮肤是敏感性的，有过过敏现象，刚我们在使用产品时，一定要在使用部位选取一小块区域试用，确定安全后方可建议其正常使用。如果使用某些产品出现了过敏反应，首先应停用该产品，一般停用后皮肤会自然恢复。如过敏反应较重，则应就医，请教皮肤科医生的专业意见。 在没有过敏前先用:清爽保温凝露或舒缓凝露打底，再使用其它产品。(对那些换过肤，使用过强效祛斑霜的顾客一定要特别小心) 换过肤的人，她的表皮层基本被破坏了，我们不能一下就站她用幻时系列高营养的产品，这样可能会增加其皮肤的负担。要使用基本的保养品逐渐保养后，再用高营养的护肤品。而那些使用过强效祛斑霜的circuit board by hand or tool, the operator shall take anti-static measures. 5.1.3.2.6 site the installation site should be installed in the enclosure with light, dry places, installation should be normal, smooth, firm, perpendicularity tolerance for 3mm/5M, horizontal gradient tolerance for 4mm/5M. 5.1.4 instrument cable tray and junction box install 5.1.4.1 cable channel should be according to the construction plan, Hsien Chu Rami. Construction should be carefully checked before the process piping and equipment layout, and check the cable trough the practical direction, ensure that the cable channel's direction and elevation do not conflict with the process piping and equipment, construction workers correctly. 5.1.4.2 slot must have the support, fixed support spacing should be 2 m, bends must have support bracket cannot be directly welded to a place with thermal expansion. 5.1.4.3 trunking interface connectors and bolts, and set appropriate expansion gap, all online slot bolt head should be inside. 5.1.4.4 slot into the control room should be fireproof and waterproof measures, online slots filled fire outside sealing mastic to prevent flammable gas into the control room. 5.1.4.5 slot when holes are needed, machining, electric and gas welding process shall not be used, open hole, the edges should be sanded smooth and touch up in a timely manner. 5.1.4.6 line after installing reliable earthing, grounding wire connected to the slot spacing shall not exceed 30m. 5.1.4.7 install junction box (1) should be installed in a light, dry place, the ambient temperature should not be more than 450C, box Center height from the ground to about 1100mm; (2) there should be good sealing practices, and identify number; (3) shall not affect the operation, maintenance and access, online slots should be installed on each side. 5.1.5 cable protection pipe preparation 5.1.5.1 instrument cable protection pipe should avoid high 皮肤，皮肤已有汞中毒的可能。(强效祛斑的原理:通过汞杀死黑色素细胞达到快速美白的功效，有很多这种类型的化妆品汞是严重超过国家标准的) 注意:在使用防晒产品时，最好先用舒缓凝露打底，再使用防晒霜。 衰老皮肤 成熟肌肤的问题 特征: 粗糙:肌肤新陈代谢减缓或受外界环境刺激，皮肤长期没有得到细心保养，会导致角质层堆积增厚，皮肤摸起来粗粗的。 干燥/缺水:肌肤步入成熟老化期，水份、养份的新陈代谢变差，荷尔蒙分泌逐年下降，肌肤含水量减少，保水力减低，出现干粗、脱皮的现象。 细纹/皱纹:年龄增长以及紫外线的影响，真皮层制造胶原纤维和弹性纤维的速度减慢，空隙开始形成。加上老化肌肤的缺水状况，便导致了皱纹的产生，特别是眼角及嘴角周围的肌肤更容易产生皱纹。 失去弹性/松驰下垂:肌肤新陈代谢减缓，导致肌肤真皮层的弹力蛋白生成速度变慢，甚至原有的弹力蛋白可能断裂。皮肤会变得脆弱、无弹性，脸部的轮廓也变得不清晰了。 失去活力/无光泽:肌肤失去重要的储备能量，诸如维生素、保湿因子和天然抗老化因子都会逐年减少，自我修复因外在环境所造成的损害也变得较为困难，肌肤失去活力，晦暗无光泽。 成因: 随着年龄、紫外线、环境、睡眠、保养不当、饮食的影响(肌肤新陈circuit board by hand or tool, the operator shall take anti-static measures. 5.1.3.2.6 site the installation site should be installed in the enclosure with light, dry places, installation should be normal, smooth, firm, perpendicularity tolerance for 3mm/5M, horizontal gradient tolerance for 4mm/5M. 5.1.4 instrument cable tray and junction box install 5.1.4.1 cable channel should be according to the construction plan, Hsien Chu Rami. Construction should be carefully checked before the process piping and equipment layout, and check the cable trough the practical direction, ensure that the cable channel's direction and elevation do not conflict with the process piping and equipment, construction workers correctly. 5.1.4.2 slot must have the support, fixed support spacing should be 2 m, bends must have support bracket cannot be directly welded to a place with thermal expansion. 5.1.4.3 trunking interface connectors and bolts, and set appropriate expansion gap, all online slot bolt head should be inside. 5.1.4.4 slot into the control room should be fireproof and waterproof measures, online slots filled fire outside sealing mastic to prevent flammable gas into the control room. 5.1.4.5 slot when holes are needed, machining, electric and gas welding process shall not be used, open hole, the edges should be sanded smooth and touch up in a timely manner. 5.1.4.6 line after installing reliable earthing, grounding wire connected to the slot spacing shall not exceed 30m. 5.1.4.7 install junction box (1) should be installed in a light, dry place, the ambient temperature should not be more than 450C, box Center height from the ground to about 1100mm; (2) there should be good sealing practices, and identify number; (3) shall not affect the operation, maintenance and access, online slots should be installed on each side. 5.1.5 cable protection pipe preparation 5.1.5.1 instrument cable protection pipe should avoid high 代谢减缓、角质层堆积增厚、肌肤含水量减少，保水能力降低、真皮层制造胶原纤维和弹性纤维的速度减慢、真皮层的弹力蛋白生成速度变慢、肌肤失去重要的储备能量)等等 发展下去的后果: 皱纹增多、皮肤更加粗糙，象桔子皮、皮肤松驰下垂，与实际年龄不相符(30岁的年龄，40岁的面容)、皮肤暗淡蜡黄无光泽，黄脸婆就是这样～即没有青春也没有美丽～ 解决办法(配方):(幻时系列产品) Retinyl Palmitate 维生素A棕榈酸脂 :紧致肌肤，减少皱纹。 维生素E衍生物:抗氧化功能 黄瓜、柠檬等植物萃取液:使肌肤保温的功能 海藻萃取精华:保温功效 多种氨基酸和吡咯酮羧酸钠复合营养保湿系统(Proden400):保持皮肤水分的同时提供丰富的营养，强化 circuit board by hand or tool, the operator shall take anti-static measures. 5.1.3.2.6 site the installation site should be installed in the enclosure with light, dry places, installation should be normal, smooth, firm, perpendicularity tolerance for 3mm/5M, horizontal gradient tolerance for 4mm/5M. 5.1.4 instrument cable tray and junction box install 5.1.4.1 cable channel should be according to the construction plan, Hsien Chu Rami. Construction should be carefully checked before the process piping and equipment layout, and check the cable trough the practical direction, ensure that the cable channel's direction and elevation do not conflict with the process piping and equipment, construction workers correctly. 5.1.4.2 slot must have the support, fixed support spacing should be 2 m, bends must have support bracket cannot be directly welded to a place with thermal expansion. 5.1.4.3 trunking interface connectors and bolts, and set appropriate expansion gap, all online slot bolt head should be inside. 5.1.4.4 slot into the control room should be fireproof and waterproof measures, online slots filled fire outside sealing mastic to prevent flammable gas into the control room. 5.1.4.5 slot when holes are needed, machining, electric and gas welding process shall not be used, open hole, the edges should be sanded smooth and touch up in a timely manner. 5.1.4.6 line after installing reliable earthing, grounding wire connected to the slot spacing shall not exceed 30m. 5.1.4.7 install junction box (1) should be installed in a light, dry place, the ambient temperature should not be more than 450C, box Center height from the ground to about 1100mm; (2) there should be good sealing practices, and identify number; (3) shall not affect the operation, maintenance and access, online slots should be installed on each side. 5.1.5 cable protection pipe preparation 5.1.5.1 instrument cable protection pipe should avoid high