秉持尊重学生和家长隐私的原则，以下所展示的信息，已经去掉敏感和涉及知识产权的信息。

还有N多学术素材，由于知识产权或家长原因，不便公开，敬请理解。

本文作者W同学，美高毕业后在全美第30名的大学就读，物理专业，专业排名第一名，Ranking 1/70。她在大学期间，参加了很多学术活动，有一定的实习经历，喜欢学习，喜欢实验室环境，希望未来能读博士走学术道路。申请美国博士，不仅仅需要GPA和GRE成绩，更需要良好扎实的科研背景和3位教授推荐信。为此，与爸爸妈妈沟通后，W同学报名参加了美国名校科研的选拔。参加美国名校科研，增加学术背景，开拓视野，获得真知。

目前美国学界现状，多学科融合发展。很多专业领域的科研突破，都来自于吸收交叉学科的前沿知识。比如：普林斯顿大学心理学教授丹尼尔与经济学教授史密斯分享诺贝尔经济学奖。这些领域的交叉科研助理招募的名额，也为学生更好申请博士奠定了现实基础。由于学生一直在美国学习，也参与了本校很多科研，了解到了学科交叉的特点，希望可以收获多学科的知识。科研申请老师将简历发送到了物理、化学、生物、统计等系别，申请科研的面试机会。非常幸运，学生获得了一所TOP5大学教授的面试机会。学生积极准备面试，获得了周期2个月的科研名额。

参与2个月的科研，可以更深入的扩充科研知识，实验设计也更加灵活。由于学生认真参与教授课题，同时与助教积极沟通，在科研结束后，顺利发表论文一篇。

我们很高兴的看到学生在这次科研学习中还有很多学术知识以外的收获，这些严谨的实验习惯养成会对未来学习大有裨益。学生在科研总结中写到：我发现这是一个很好的办法（及时记录实验想法）对于未来实验，因为每个人都有不同的记忆和通常的细节事情会被遗忘一段时间后，结束一切又是浪费时间和资源，所以我学会了在每个实验后为未来写下注意实验。

作为科研申请老师，我们想告诉每位参与美国科研的孩子，获得推荐信、科研证书、科研报告、科研履历，其实仅仅是美国科研的基础性收获。更为重要的是，学生通过与顶尖学者、专家的交流，树立了长期的学术目标，让学术能力伴随着生命的成长而发展，让学术赞美生命！

美国科研就是背景提升，目标就是提高本、硕、博录取质量。

科研总结

本文是学生在美国大学科研学习结束后所写的感受，并在文后附录了学生的科研论文和推荐信，供参考。

注：中文译文是编辑进行的整理，英语能力较好的学生和家长建议直接阅读英文。

第一个月

I earned so many lab experiences from first two weeks work with Professor. Firstly we were learning how to use pipettes accurately for the future experiments and I read a paper about glucose metabolism via the pentose phosphate pathway for my future research project. Later two days I learned the dissection of mouse and rat, and I also work on the mouse dissection to collect liver, two kidneys, skeletal muscles, brain, skin and brown fat samples from those mice. Professor taught me patiently about how to use the dissection tools and how to figure out the position of different organs.
在和教授共事的头两周，我收获了很多实验经验。首先，我们在学习如何在未来的实验中准确地使用吸管，为了我未来的研究项目，我阅读了一篇关于戊糖磷酸途径葡萄糖代谢的论文。之后的两天，我学习了小鼠和大鼠的解剖，我也做了小鼠的解剖工作，收集了小鼠的肝脏、两个肾脏、骨骼肌、大脑、皮肤和棕色脂肪样本。

Furthermore, Professor provided me the opportunity to watch his colleague to perfuse the mouse heart P-31 to let me roughly got the idea of how does the perfuse mostly performed and we also work on P-31 rat heart last week and we detected Pi, PCr, g-ATP, a-ATP, b-ATP. During the experiment we faced many troubles like the buffer was always leaking and the balloon was broke, and we did lots of troubleshoot and remade the balloon with condom. I also learned how to set up and turn on the switches for the buffer flowing correctly. Later on we collected the eight spectra and did the NMR data analysis using the vnmrj software. Professor always patiently explain everything in detail to show me how to analyze NMR data using both vnmrj software and Excel to get the concentration comparison of Pi, PCr, g-ATP, a-ATP, b-ATP in two different analysis ways.
此外，教授还让我有机会观看他的同事为小鼠心脏P-31灌注，让我大致了解灌注主要是如何进行的，上周我们也对P-31大鼠心脏进行了研究，我们检测到了Pi、PCr、g-ATP、a-ATP、b-ATP。在实验过程中，我们遇到了很多问题，比如缓冲器总是漏水，气球坏了，我们做了很多的故障排除，。我还学习了如何正确地设置和打开缓冲流的开关。之后我们收集了8个光谱，利用vnmrj软件进行了核磁共振数据分析。教授总是耐心地讲解每一件事的细节，向我展示如何利用vnmrj软件和Excel分析NMR数据，得到Pi、PCr、g-ATP、a-ATP、b-ATP两种不同分析方法的浓度比较。

Moreover, Professor and I were preparing the extracts for C-13 NMR following the step-by-step protocol, and I gained lots of biology experiment knowledge such as how to use different machines such as centrifuge machine and how to change the oil for Lyophilize. Also, we went to a great seminar about the “The Dog Aging Project: Genetic and Environmental Determinants of Healthy Aging” given by Professor for connecting genetic and environment variables, some interesting facts he found really attract me a lot such as the smaller size of the same breed of dogs can have longer lifespan; different breed of dogs have different types for the high risk cancer; and so on. I’m still doing the C-13 NMR lab for the mouse heart, and thanks for Professor’s huge help to let me always learn the new knowledge and be aware of how to perform accurately from all the aspects.
此外，我和教授按照一步一步的步骤来准备C-13 NMR的萃取物，我学到了很多生物学实验知识，比如如何使用不同的机器，比如离心机，如何更换油进行冻干。我们去了一个伟大的研讨会“狗老化项目:遗传和环境因素的健康老龄化”由教授连接遗传和环境变量,一些有趣的事实他发现真的吸引我很多,比如小的大小相同品种的狗可以有较长的使用寿命;不同品种的狗患高风险癌症的类型也不同;等等。我还在做小鼠心脏的C-13 NMR实验室，感谢教授的巨大帮助，让我一直学习新的知识，知道如何从各个方面准确的执行。

In the second two weeks, I started to mainly focus on how to use NMR machine and do the better job at tuning, lock and shim. The first one I did is the mouse heart in C-12 and there are only six peaks has been detected in the C-12 with reference chemical shift 67.4 ppm (Dioxane). I also learned how to change the probes, there are three probes I changed in this summer: P-31 20mm probe, C-13 10mm probe and C-13 3mm probe(mostly used this one). VT is for the temperature setting and if the temperature is not good, I need to reset VT first and set the airflow as 10 and regulate the temperature again. Also, the spin needs to be set before the tuning but at first we the spin can be 20Hz but later on I don’t know why later on we only can do the spin at 13Hz and 8Hz.
在接下来的两周，我开始主要关注如何使用NMR机器，以及如何更好的调优锁片。我做的第一个实验是C-12中的小鼠心脏，在参考化学位移67.4 ppm(二恶烷)的情况下，C-12中只检测到6个峰。我还学会了如何更换探头，今年夏天我换了三个探头:P-31 20mm探头，C-13 10mm探头，C-13 3mm探头(主要用这个)。VT是温度设置，如果温度不好，我需要先重置VT，将气流设置为10，然后再调节温度。同样，自旋需要在调弦之前设置但一开始我们的自旋可以是20Hz，但后来我不知道为什么后来我们只能在13Hz和8Hz处进行自旋。

I also had a small lecture on HPLC so from the lecture, I learned basic knowledge about the principle and advantages for HPLC. Although I don’t need to do with HPLC but I think this mini lecture is still very useful for expanding my knowledge area.
我也有一个关于HPLC的小讲座，从讲座中，我学到了HPLC的原理和优点的基本知识。虽然我不需要使用HPLC，但是我认为这个小讲座对于扩大我的知识面还是非常有用的。

Later on, I prepared two extracts for C-13 labeled heart by myself, one is the universial C-13 glucose labeled heart and one is the 1-C13 glucose labeled heart. This is the second time I was doing the extract but the first time doing it by myself so I tried to conclude more details to the protocol from my previous experience for C-13 extract preparation such as the homogenization need to be down in the ice and if I don’t mark down, I will forget the next time. I found this is a really good way to do the future experiments because everyone has different memory and usually the detail things will be forgotten after a while and concluding everything again is wasting time and resource, so I learned after each experiment I need to write down my own notice for my future experiment.
后来，我自己为C-13标记心脏准备了两种提取物，一种是通用的C-13葡萄糖标记心脏，另一种是1-C13葡萄糖标记心脏。这是我第二次做提取但是自己第一次做所以我试图得出更多细节协议从我以前的经验等c13提取制备均匀化需要在冰和如果我没有记下,下次我会忘记。我发现这是一个很好的办法对于未来实验，因为每个人都有不同的记忆和通常的细节事情会被遗忘一段时间后，结束一切又是浪费时间和资源，所以我学会了在每个实验后为未来写下注意实验。

On the other hand, after Professor pointed out the main issue relates to my pipette skills, my pipette improved a lot and getting more accurate by then. I know how to centrifuge and how to adjust the units from rpm to rcm. I also know how to change the engine oil and how to use the Lyopholize machine (Labconco model 117), which can directly transfer the solid solution to concentrated powder (temperature mostly -56C and the vacuum level is 0.002 mBr).
另一方面，在助教博士指出主要问题与我的移液管技能有关之后，我的移液管有了很大的进步，到那时，我的移液管变得更加准确。我知道如何离心和如何调整单位从rpm到rcm。我还知道如何更换机油，如何使用Lyopholize 机器(Labconco型号117)，它可以直接将固溶体转化为浓缩粉末(温度大多为-56C，真空级别为0.002 mBr)。

Later on, I did a very interesting experiment that I ejected the rat blood to store in 4℃ refrigerator and let the rat heart to the P-31 NMR test. Then I take out the rat heart blood and try to use warm water bath and vortex to dissolve the plasma precipitate down the tube but there is still some precipitate down there so I added 1.5ml Heparin sodium to solve a little bit more and transport to big tube for P-31 NMR test. In this test there are two spectra collected and there are totally 7 peaks. For the comparison, I collected the second tube of sample and added 400ul 75mM Na2HPO4 in 50% D2O and 400u 100mM PPA and centrifuge the blood for 5000 rpm 10min and both the blood the supernant were collected for P-31 NMR test and I only got 4 peaks for supernant and 8 peaks for original sample. For the next time I probably will do the blood NMR test as soon as possible so it will has less precipitation and the results can be more accurate and interesting.
后来，我做了一个非常有趣的实验，我把大鼠的血液喷射到4℃的冰箱中储存，让大鼠的心脏进行P-31 NMR测试。然后我拿出大鼠心脏血液和尝试使用温水沐浴和涡等离子体溶解沉淀下来管,但仍有一些沉淀下来所以我添加1.5毫升肝素钠解决一点和运输为31页大管核磁共振测试。本实验共采集了两个光谱，共7个峰。通过比较，我采集了第二管样品，在50% D2O中加入400ul 75mM Na2HPO4，在400u 100mM PPA中加入400u Na2HPO4，离心血液5000转/分钟10min，取两个供体的血液进行P-31核磁共振测试，仅取4个供体的峰值和8个原始样本的峰值。下次我可能会尽快做血液NMR测试，这样沉淀就会更少，结果也会更准确和有趣。

第二个月

This month is mainly focus on the research project for the PPP (pentose phosphate pathway) activity by doing C-13 NMR in effluents. In the mouse heart perfusion, a small balloon was placed inside and dioxane tube was placed for standard, and the buffer is for beating. As we don’t have D2O inside so we don’t need to do the lock but only do the shim. The temperature was set as 37℃ which is the normal body temperature. In the entire three-hour process, the first 30 min is for C-12 glucose, and the later 60min is for C-13 glucose in normal perfusion, and the last 90 min is for low flow ischemia C-13 glucose perfusion. We collected is second 60min part effluent (E1) and final 90 min effluent (E2) for NMR detection and heart was collected for the MDA assay and the protein assay detection. There are totally 15 hearts in my research so I tested 30 effluents (E1 and E2 for one heart).
这个月主要集中在污水中进行C-13 NMR研究PPP(戊糖磷酸途径)活性的项目。在小鼠心脏灌注时，将一个小球囊放入其中，标准放置二恶英管，缓冲液用于跳动。因为里面没有D2O所以我们不需要锁，只需要垫片。温度设定为37℃，为正常体温。在整个3小时的过程中，前30min为C-12葡萄糖，后60min为正常灌注时的C-13葡萄糖，后90min为低流量缺血时的C-13葡萄糖灌注。收集第二批60min部分出水(E1)和最后一批90min出水(E2)进行NMR检测，收集心脏进行MDA检测和蛋白检测。在我的研究中总共有15颗心脏，所以我测试了30种流出物(一颗心脏的E1和E2)。

Basically, after the effluents were lyopholized in Lyopholize machine, 300ul D2O and 5ul dioxane was added, and mostly around 18ul HCL (5N) was added for neutral PH adjustment. There are so many interesting chemicals I detected from NMR: isocitrate, D-hydroxy butyrate, gluconate, citrate, bicarbonate, b-glucose, DHAP(Hydrate), NADH, a-glucose, b-glucose, a-Fructose, b-Fructose, inositol (myo), glycerol, a-atrehalose, glycogen(1->4), glycogen (1->6), malate, Glycerol, lactate, glutamate, glutamine.
基本上,废水在Lyopholize lyopholized机后,添加了300 ul D2O和ul二氧六环,和大部分18 ul盐酸(5 n)添加中性PH值调整。核磁共振检测到很多有趣的化学物质:异柠檬酸、d -羟基丁酸盐、葡萄糖酸盐、柠檬酸盐、碳酸氢盐、b-葡萄糖、DHAP(水合物)、NADH、a-葡萄糖、b-葡萄糖、a-果糖、b-果糖、肌醇(肌醇)、甘油、a-阿特拉糖、糖原(1->4)、糖原(1->6)、苹果酸盐、甘油、乳酸、谷氨酸、谷氨酰胺。

The one we are going to analyze is the lactate third carbon and it has two high peak doublets and one small singlet in the middle. I can directly use the integration in vnmrj software to get the percentage for the singlet, which is standing for the PPP activity for later calculation. Also I did the integration comparison between b-glucose second carbon (chemical shift: 75.2ppm) and the Lactate third carbon to get the protein content (concentration) of the lactate for later calculation. By the rough calculation is peak of the E2 is much higher than E1, which means the lactate concentration in E2 is much higher than E1, so the low flow ischemia perfusion has higher PPP activity.
我们要分析的是乳酸三碳它有两个高峰双峰和一个小单峰在中间。我可直接使用vnmrj软件中的积分，得到单重线的百分比，表示PPP活动，用于以后的计算。并对b-葡萄糖二碳(化学位移:75.2ppm)与乳酸三碳进行积分比较，得到乳酸的蛋白含量(浓度)，供以后计算。粗略计算，E2的峰值远高于E1，这意味着E2中的乳酸浓度远高于E1，因此低流量缺血灌注具有较高的PPP活性。

Later on, I prepared the MDA and lowry protein sample for 15 hearts that I did for their effluent detection in C13 NMR. 600ul 1N PCA and 6ul BHT was added to the tissue and homogenize well to collect 100ul for protein assay and rest of the sample was centrifuged to get the supernant for MDA assay. I made the TBA reagent for MDA and each testing tube contains 200ul supernant and 600ul TBA reagent, and all samples need to transfer to special cuvette and do both colorimetric and fluorometric analysis (absorbance at 532nm).
之后，我为15颗心脏准备了MDA和低蛋白样品，并在C13 NMR中对它们的出水进行检测。向组织中加入600ul 1N PCA和6ul BHT，匀浆均匀，取100ul进行蛋白检测，其余离心，取上清液进行MDA检测。我做了MDA的TBA试剂，每根测试管含有200ul上清液和600ul TBA试剂，所有样品需要转移到专用试管中，并进行比色和荧光分析(532nm吸光度)。

I also learned how to use the software UV Winlab to do the setup and detection, it is better to use the single cell to detect all the sample and standard solution which can has more accurate data. After that I can collect all the data I get from MDA assay, lowry assay, NMR PPP activities and NMR lactate protein content for the calculation and data analysis. The most of the data analysis were done in the Microsoft Excel and the figures and diagrams were from the Prism software, which is very strong software for data analysis.
我还学习了如何使用UV Winlab软件进行设置和检测，最好使用单细胞检测所有的样品和标准溶液，这样可以有更准确的数据。然后我可以收集所有我从MDA分析，lowry分析，NMR PPP活性和NMR乳酸蛋白含量得到的数据进行计算和数据分析。大部分的数据分析都是在Microsoft Excel中完成的，图表都来自Prism软件，这是一个非常强大的数据分析软件。