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Science & technology
科技版塊
Contraception
避孕
Tubular gels
管狀凝膠
Researchers want to make reversible vasectomies a one shot deal
研究人員希望使可逆輸精管切除術(shù)成為一種一次性解決方案
The most reliable means of contraception for men--and one that cannot fail or be forgone in the heat of the moment--is a vasectomy.
對男性來說，最可靠的避孕方法是輸精管結(jié)扎術(shù)，這是一種不會在一時的狂熱中失敗的方法。
But the procedure is largely irreversible: it involves stopping the flow of sperm from the testes by cutting conduits known as the vas deferens and sealing them or tying them off.
但這一過程在很大程度上是不可逆轉(zhuǎn)的：它包括通過切割被稱為輸精管的管道來阻止精子從睪丸流出，并將它們密封或打結(jié)。
A reconnection, after a reconsideration, is no small task.
在重新考慮之后，重新建立聯(lián)系并不是一項小任務(wù)。
Researchers are now examining a different tack: blocking the vas deferens using compounds that combine to form a barrier that can later be removed.
研究人員現(xiàn)在正在研究一種不同的方法：使用化合物來堵塞輸精管，這些化合物結(jié)合在一起形成一道屏障，以后可以被移除。
Lab trials have involved four separate injections to establish a sperm-proof barrier, which could later be dissolved using a blast of focused, infrared light.
實驗室試驗包括四次單獨的注射，以建立防精子屏障，之后可以用一束聚焦的紅外光來溶解它。
Aware that repeated injections into the penis might affect men’s willingness to undergo such a procedure, Wanhai Xu, a urologist at Harbin Medical University in China, and colleagues propose a different idea: a barrier that can be put in place with one injection and broken down with ultrasound.
中國哈爾濱醫(yī)科大學(xué)的泌尿科醫(yī)生徐萬海和他的同事們意識到，陰莖反復(fù)注射可能會影響男性接受這種手術(shù)的意愿，因此他們提出了一個不同的想法：只需注射一次就能建立屏障，然后通過超聲波消除。
Dr Xu’s recipe includes three parts, principally a polymer known as a hydrogel that thickens inside the body and is already approved for medical use.
徐博士的方法包括三個部分，主要是一種被稱為水凝膠的聚合物，它會在體內(nèi)增稠，已經(jīng)被批準(zhǔn)用于醫(yī)療用途。
Crucially, in that gel were plenty of thioketals, compounds that fall apart when exposed to reactive, oxygen-containing molecules, plus just a sprinkle of titanium dioxide--an inert material that, when exposed to ultrasound, releases just those molecules.
至關(guān)重要的是，這種凝膠中含有大量的硫酮化合物，這種化合物接觸到活性的含氧分子就會分解，外加少量二氧化鈦--一種惰性物質(zhì)，暴露在超聲波下時，這些分子就會被釋放。
To check their work, Dr Xu’s team employed a few dozen male rats.
為了檢驗他們的工作，徐博士的團隊使用了幾十只雄性老鼠做實驗。
Some were given a traditional vasectomy, others an injection of the new material and the rest injected with saline, as a control.
一些老鼠接受了傳統(tǒng)的輸精管結(jié)扎術(shù)，另一些注射了新材料，其余的注射了生理鹽水作為對照。
Each was then permitted to follow its essential nature with four females.
每只老鼠都可以與四只雌性老鼠自由交配。
Only those rats given the saline sired offspring.
只有那些注射了生理鹽水的老鼠能繁殖后代。
The real test, as the team reports in acs Nano, a nanotechnology journal, came next: half the rats given the new treatment were exposed to a blast of ultrasound.
接下來，研究小組在納米技術(shù)期刊《acs Nano》上發(fā)表了真正的測試：接受新實驗的老鼠中有一半暴露在超聲波沖擊波下。
That evidently dissolved the hydrogel in the creatures’ pipes: they could again reproduce, while those not thusly blasted stayed sterile.
很明顯，在超聲波下，老鼠體內(nèi)的水凝膠溶解了，它們可以再次繁殖，而那些沒有暴露在超聲波下的老鼠依然不能生育。
What works in rats, alas, does not always work in humans, so further trials will be needed.
可惜的是，在老鼠身上有效的方法在人類身上并不總是有效，因此還需要進一步的試驗。
But Dr Xu is hopeful that these findings represent a sound idea for a reversible contraceptive--with fewer sticking points.
但徐博士希望這些發(fā)現(xiàn)代表了可逆避孕的一個可靠想法--減少結(jié)扎。
