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  • The earliest known pregnancy test dates back to 1350 BC in Ancient Egypt.

    現在知られている最古の妊娠検査は 紀元前1350年の古代エジプトに遡ります

  • According to the Egyptians,


  • all you have to do is urinate on wheat and barley seeds, and wait.


  • If either sprouts, congratulations, you're pregnant!

    どちらかに芽が出れば おめでとうございます! 御懐妊です!

  • And if wheat sprouts faster, it's a girl, but if barley, it's a boy.

    そして小麦が先に芽が出れば女の子 大麦であれば男の子です

  • In 1963, a small study reproduced this test

    1963年に このテストの 再現実験が行われ

  • and found that it predicted pregnancy with a respectable 70% accuracy,

    ほぼ70%の確率で 妊娠を判別できることが分かりました

  • though it couldn't reliably tell the sex of the baby.

    ただし 子供の性別までは 正しく判別できませんでした

  • Scientists hypothesized that the test worked

    科学者はこのテストが 有効であると考えました

  • because pregnant women's urine contains more estrogen, which can promote seed growth.

    なぜなら妊娠した女性の尿は 多くの女性ホルモンを含み

  • Now it's easy to take this ancient method for granted


  • because modern pregnancy tests give highly accurate results within minutes.

    現代は当たり前のように この古代の方法を行うことができます

  • So how do they work?

    なぜなら現代の妊娠検査は 数分間でとても正確な結果を出すからです

  • Over-the-counter pregnancy tests are all designed to detect one thing: a hormone called HCG.


  • HCG is produced in the earliest stages of pregnancy

    市販の全ての妊娠検査は ある物質を検知するように設計されています

  • and starts a game of telephone that tells the body not to shed the inner lining of the uterus that month.


  • As the pregnancy progresses, HCG supports the formation of the placenta,


  • which transfers nutrients from mother to fetus.


  • The test starts when urine is applied to the exposed end of the strip.

    その月に子宮の内壁が脱落しないよう 母体に伝えるのです

  • As the fluid travels up the absorbent fibers,


  • it will cross three separate zones, each with an important task.


  • When the wave hits the first zone, the reaction zone,


  • Y-shaped proteins called antibodies will grab onto any HCG.

    このテストは紙切れの端に 尿をつけると始まります

  • Attached to these antibodies is a handy enzyme with the ability to turn on dye molecules,


  • which will be crucial later down the road.

    それぞれ重要な役目をもつ 3つの区間を通ります

  • Then the urine picks up all the AB1 enzymes and carries them to the test zone, which is where the results show up.


  • Secured to this zone are more Y-shaped antibodies that will also stick to HCG on one of its five binding sites.

    抗体と呼ばれるY型のタンパク質が hCGを捕まえます

  • Scientists call this type of test a sandwich assay.

    これらの抗体には それ以降の過程で重要となる

  • If HCG is present, it gets sandwiched between the AB1 enzyme and AB2,

    色素分子を発色させる能力を持った 便利な酵素が結合しています

  • and sticks to the test zone, allowing the attached dye-activating enzyme to do its job and create a visible pattern.


  • If there's no HCG, the wave of urine and enzymes just passes on by.

    テスト区域に移動させると 結果が現れます

  • Finally, there's one last stop to make, the control zone.

    この区域には さらにY型の抗体があり

  • As in any good experiment, this step confirms that the test is working properly.

    hCGの5つの結合部位の1つに 結合します

  • Whether the AB1 enzymes never saw HCG,

    科学者はこのタイプのテストを サンドイッチアッセイと呼びます

  • or they're extras because Zone 1 is overstocked with them,

    hCGが存在すると AB1とAB2酵素の間に挟まれ

  • all the unbound AB1 enzymes picked up in Zone 1 should end up here and activate more dye.


  • So if no pattern appears, that indicates that the test was faulty.


  • These tests are pretty reliable, but they're not failproof.


  • For instance, false negatives can occur if concentrations of HCG aren't high enough for detection.

    もしhCGがなければ 尿と酵素は単に区間を通り抜けてしまいます

  • After implantation, HCG levels double every two to three days, so it may just be too early to tell.


  • And beverages can dilute the urine sample,


  • which is why doctors recommend taking the test first thing in the morning.

    この段階で実験が正しく 機能していることを証明します

  • On the other hand, false positives can come from other sources of HCG,


  • like IVF injections, ectopic pregnancies,


  • or certain cancers such as uterine cancer or testicular cancer,

    最初の区間にあった 全ての未結合AB1酵素がここまで運ばれ

  • making it possible for one of these tests to tell a man he's pregnant.


  • The best way for a woman to find out for sure is at the doctor's office.

    もし何の模様も現れなければ 検査は失敗であることを示します

  • The doctors are also looking for HCG,

    これらの検査はかなり信頼性が高いものの 完全なものではありません

  • but with tests that are more sensitive and quantitative,


  • which means they can determine the exact level of HCG in your blood.

    例えばhCGの濃度が 検知されるほど十分でない場合です

  • A few minutes can feel like forever when you're waiting on the results of a pregnancy test.

    受精卵の着床後に hCGの濃度は2、3日毎に倍増します

  • But in that brief time, you're witnessing the power of the scientific method.


  • That one little stick lets you ask a question,


  • perform a controlled experiment,

    それが医師が朝一番に 検査することを勧める理由です

  • and then analyze the results to check your original hypothesis.

    その一方で 誤った陽性反応も hCGの他の発生源―

  • And the best part is you won't even have to wait until the next harvest.


The earliest known pregnancy test dates back to 1350 BC in Ancient Egypt.

現在知られている最古の妊娠検査は 紀元前1350年の古代エジプトに遡ります


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B2 中上級 日本語 TED-Ed 酵素 検査 結合 テスト 抗体

TED-ED】妊娠検査ってどうやってするの?- ティエン・グエン (【TED-Ed】How do pregnancy tests work? - Tien Nguyen)

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    SylviaQQ に公開 2021 年 01 月 14 日